Adding the model "Post" to my admin views makes someone quite angry. The repo with the rest of the code can be found at https://github.com/cldershem/homelessgaffer .

admin.py

from flask.ext.admin import (Admin, BaseView, AdminIndexView, expose)
from app import app, db
from flask.ext.admin.contrib.mongoengine import ModelView
from models import User, Post, Page
from utils import CKTextAreaField

class AdminView(BaseView):
    @expose('/')
    def index(self):
        return self.render('index.html')

class UserView(ModelView):
    column_filters = ['email']

class PostView(ModelView):
    column_filters = ['title']

class PageView(ModelView):
    column_filters = ['title']    

    #form_overrides = dict(content=CKTextAreaField)
    #create_template = 'admin/edit.html'
    #edit_template = 'admin/edit.html'

admin = Admin(app)

admin.add_view(UserView(User))
admin.add_view(PostView(Post))
admin.add_view(PageView(Page))

forms.py

from flask.ext.wtf import Form
from wtforms import ( TextField, TextAreaField, validators, PasswordField,
                      SubmitField, BooleanField, ValidationError )
from wtforms.validators import Required, EqualTo
from models import db, User, Post, Comment, Page
from mongoengine.queryset import DoesNotExist
from utils import makeSlug, CKTextAreaField

class LoginForm(Form):
    email = TextField('email', [validators.Required(
                        "Please enter a username.")])
    password = PasswordField('password', [validators.Required(
                            "Please enter a password")])
    remember_me = BooleanField('remember me')
    submit = SubmitField("login")
    
    def __init__(self, *args, **kwargs):
        Form.__init__(self, *args, **kwargs)

    def validate(self):
        if not Form.validate(self):
            return False
        
        try:
            user = User.objects.get(email = self.email.data.lower())
        except DoesNotExist:
            self.email.errors.append("Invalid email address")
            return False
        if user and user.check_password(self.password.data):
            return True
        else:
            self.password.errors.append("Invalid password")
            return False

class RegisterUser(Form):
    
    firstname = TextField("First name",  [validators.Required(
                            "Please enter your first name.")])
    lastname = TextField("Last name",  [validators.Required(
                            "Please enter your last name.")])
    email = TextField("Email",  [validators.Required(
                        "Please enter your email address."), 
                        validators.Email(
                        "Please engter a valid email address.")])
    password = PasswordField('New Password', [validators.Required(), 
                             EqualTo('confirm', 
                             message='Passwords must match')])
    confirm = PasswordField('Confirm', [validators.Required(
                                "Password again, please.")])
    submit = SubmitField("Create account")
       
    def __init__(self, *args, **kwargs):
        Form.__init__(self, *args, **kwargs)

    def validate(self):
        if not Form.validate(self):
            return False

        try:
            user = User.objects.get(email=self.email.data.lower())
            self.email.errors.append("That email already exists.")
            return False
        except DoesNotExist:
            return True

class PostForm(Form):

    title = TextField("Title", [validators.Required(
                        "Please enter a title for your post.")])
    body = CKTextAreaField("Body", [validators.Required(
                        "Please enter a body to your post.")])
    tags = TextField("Tags") 
    submit = SubmitField("Create Post")

    def __init__(self, *args, **kwargs):
        Form.__init__(self, *args, **kwargs)
    
    def validate(self):
        if not Form.validate(self):
            return False
        try:
            newSlug = makeSlug(self.title.data)
            slug = Post.objects.get(slug=newSlug)
            self.slug.errors.append("That title already exists.")
            return False
        except DoesNotExist:
            return True

class CommentForm(Form):

    comment = TextAreaField('comment', [validators.Required()])
    submit = SubmitField("submit")

class PageForm(Form):

    title = TextField("Title", [validators.Required(
                    "Please enter a title for your page.")])
    content = CKTextAreaField("Content", [validators.Required(
                            "Please enter content for your page.")])
    submit = SubmitField("Submit Page")
    
    def validate(self):
        if not Form.validate(self):
            return False
        try:
            slug = makeSlug(self.title.data)
            page = Page.objects.get(slug=slug) 
            self.title.errors.append("That page already exists.")
            return False
        except DoesNotExist:
            return True
   

models.py

import datetime
from flask import url_for
from app import app, db
from werkzeug import generate_password_hash, check_password_hash
from utils import makeSlug 

class User(db.Document):

    class Roles(db.EmbeddedDocument):
        can_login = db.BooleanField(required=True, default=True)
        can_comment = db.BooleanField(required=True, default=True)
        can_post = db.BooleanField(required=True, default=True)
        is_admin = db.BooleanField(required=True, default=False)

    created_at = db.DateTimeField(default=datetime.datetime.now, 
                                    required=True)
    firstname = db.StringField(max_length=64)
    lastname = db.StringField(max_length=100)
    email = db.StringField(max_length=120, unique=True)
    pwdhash = db.StringField(max_length=54)
    roles = db.EmbeddedDocumentField(Roles, default=Roles)

    def set_password(self, password):
        self.pwdhash = generate_password_hash(password)
        
    def check_password(self, password):
        return check_password_hash(self.pwdhash, password)
        
    def is_authenticated(self):
        return True

    def is_active(self):
        return True

    def is_anonymous(self):
        return False 

    def get_id(self):
        return self.email

    def __repr__(self):
        return '<User %r, %r>' % (self.firstname, self.email)

class Post(db.Document):

    created_at = db.DateTimeField(default=datetime.datetime.now, required=True)
    title = db.StringField(max_length=255, required=True)
    slug = db.StringField(max_length=255, required=True)
    author = db.ReferenceField(User)
    body = db.StringField(required=True)
    tags = db.ListField(db.StringField(max_length=50))
    comments = db.ListField(db.EmbeddedDocumentField('Comment'))

    def get_absolute_url(self):
        return url_for('post', kwargs={"slug": self.slug})

    def __unicode__(self):
        return self.title

    meta = {
            'allow_inheritance': True,
            'indexes': ['-created_at', 'slug'],
            'ordering': ['-created_at']
            }
    
    def __repr__(self):
        return '<Post %r, -%r>' % (self.slug, self.author)

class Comment(db.EmbeddedDocument):

    created_at = db.DateTimeField(default=datetime.datetime.now, 
                                  required=True)
    body = db.StringField(required=True)
    author = db.ReferenceField(User)

    def __repr__(self):
        return '<Post %r>' % (self.author)

class Page(db.Document):

    created_at = db.DateTimeField(default=datetime.datetime.now, 
                                  required=True)
    title = db.StringField(required=True)
    slug = db.StringField(required=True)
    content = db.StringField(required=True)
    author = db.ReferenceField(User)

    meta = {
            'allow_inheritance': True,
            'indexes': ['-created_at', 'title'],
            'ordering': ['-created_at']
            }
    
    def __repr__(self):
        return '<Page %r>' % (self.title)

traceback

 ./run.py 
Traceback (most recent call last):
  File "./run.py", line 2, in <module>
    from app import app
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/app/__init__.py", line 15, in <module>
    from app import routes, models, admin
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/app/admin.py", line 28, in <module>
    admin.add_view(PostView(Post))
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/contrib/mongoengine/view.py", line 105, in __init__
    super(ModelView, self).__init__(model, name, category, endpoint, url)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/model/base.py", line 371, in __init__
    self._refresh_cache()
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/model/base.py", line 387, in _refresh_cache
    self._create_form_class = self.get_create_form()
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/model/base.py", line 594, in get_create_form
    return self.get_form()
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/model/base.py", line 586, in get_form
    return self.scaffold_form()
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/contrib/mongoengine/view.py", line 240, in scaffold_form
    converter=self.model_form_converter())
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/contrib/mongoengine/form.py", line 63, in model_form
    converter=converter)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_mongoengine/wtf/orm.py", line 268, in model_form
    field_dict = model_fields(model, only, exclude, field_args, converter)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_mongoengine/wtf/orm.py", line 236, in model_fields
    field = converter.convert(model, model_field, field_args.get(name))
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_mongoengine/wtf/orm.py", line 78, in convert
    return self.converters[ftype](model, field, kwargs)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/contrib/mongoengine/form.py", line 35, in conv_List
    unbound_field = self.convert(model, field.field, {})
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_mongoengine/wtf/orm.py", line 78, in convert
    return self.converters[ftype](model, field, kwargs)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/contrib/mongoengine/form.py", line 50, in conv_EmbeddedDocument
    form_class = model_form(field.document_type_obj, field_args={})
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_admin/contrib/mongoengine/form.py", line 63, in model_form
    converter=converter)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_mongoengine/wtf/orm.py", line 268, in model_form
    field_dict = model_fields(model, only, exclude, field_args, converter)
  File "/home/cldershem/Documents/Development/homelessgaffer.com/hg-Python/venv/local/lib/python2.7/site-packages/flask_mongoengine/wtf/orm.py", line 220, in model_fields
    raise TypeError('model must be a mongoengine Document schema')
TypeError: model must be a mongoengine Document schema