Set a form to use the shadowModel of the controller, and changes won't be saved back to the model (and your list-of-models next to the form) until you call `save()`. Will probably break with relationships, that'll need fixing.

edit.hbs

{{#em-form model=shadowModel}}
    {{em-input property="name" label="Name"}}
    {{em-input property="slug" label="Slug"}}
{{/em-form}}

my-controller.js

import Ember from 'ember';
import ShadowController from 'shadow-controller';

export default Ember.ObjectController.extend(ShadowController, {
});

shadow-controller.js

import Ember from 'ember';

export default Ember.Mixin.create({
  _shadowedProperties: [],
  shadowModel: function() {
    var shadow = Ember.Object.create();
    this.get("model").eachAttribute((name) => {
      this._shadowedProperties.push(name);
      shadow.set(name, this.get("model").get(name));
    });
    return shadow;
  }.property("model"),
  save: function() {
    var properties = this.get("shadowModel").getProperties(this._shadowedProperties);
    this.get("model").setProperties(properties);
    this.get("model").save();
  }
});