Minha configuração atual de deploy, usada no projeto http://mobdoctor.me Otimizações são bem vindas :)

fabfile.py

# coding: utf-8

from fabric.api import env, cd, run, sudo
from fabric.contrib.files import exists
from fabric.colors import green
from config import (HOST, USER, PASSWORD, APP_DIR,
                    ENV_HOME, PROJECT_NAME, VIRTUALENVS, REPOSITORY, BRANCH)

env.hosts = [HOST]
env.user = USER
env.password = PASSWORD
env.app_dir = APP_DIR
env.home = ENV_HOME
env.project_name = PROJECT_NAME
env.virtualenv_dir = VIRTUALENVS


def _create_ve(project_name):
    if not exists(env.virtualenv_dir):
        run('mkdir ~/.virtualenvs')
    if not exists(env.virtualenv_dir + project_name):
        with cd(env.virtualenv_dir):
            mkvirtualenv = 'virtualenv {0}'
            run(mkvirtualenv.format(project_name))
    else:
        print 'Virtualenv {0} already exists, skipping...'.format(
            env.project_name
        )


def _run(command, pip=''):
    run('{venv}{project_name}/bin/{target} {command}'.format(
        venv=env.virtualenv_dir,
        project_name=env.project_name,
        command=command, target=pip or 'python'))


def _update_app():
    with cd(env.app_dir):
        run('git pull origin {0}'.format(BRANCH))
        _run('install -r requirements.prod.txt', 'pip')
        _run('manage.py syncdb')
        _run('manage.py migrate')
        _run('manage.py collectstatic')


def _restart_app():
    sudo('service nginx restart')
    sudo('supervisorctl restart {project_name}'.format(**env))


def deploy():
    _update_app()
    _restart_app()


def setup_nginx():
    with cd('/etc/nginx/sites-enabled/'):
        sudo('touch {0}'.format(env.project_name))
        with open('nginx') as nginx:
            format_dict = {
                'project_name': env.project_name,
                'host': HOST, 'user': env.user
            }
            text = ''.join(nginx.readlines()) % format_dict
            sudo("echo '{0}' > {1}". format(text, env.project_name))


def setup_supervisor():
    with cd('/etc/supervisor/conf.d/'):
        sudo('touch {0}.conf'.format(env.project_name))
        with open('supervisor') as supervisor:
            text = ''.join(supervisor.readlines()).format(
                project_name=env.project_name, user=env.user
            )
            sudo("echo '{0}' > {1}.conf". format(text, env.project_name))
    sudo("supervisorctl reload")


def bootstrap():
    _create_ve(env.project_name)
    if not exists('~/{0}'.format(env.project_name)):
        run('git clone {0}'.format(REPOSITORY))
    setup_nginx()
    setup_supervisor()
    _update_app()
    _restart_app()
    print green('Well done!')

gunicorn.conf.py

import multiprocessing

user = "user"
workers = multiprocessing.cpu_count() * 2 + 1
bind = "localhost:some_port"
pidfile = "/tmp/mobdoctor.pid"
name = "mobdoctor"
backlog = 2048
logfile = "home/user/logs/gunicorn.mobdoctor.log"

nginx

server {
    listen 80;
    server_name mobdoctor.me;

    location /static/ {
        alias /home/%(user)s/%(project_name)s/%(project_name)s/static_files/;
        expires 30d;
    }

    location /media/ {
        alias /home/%(user)s/%(project_name)s/%(project_name)s/media/;
        expires 30d;
    }

    access_log /home/%(user)s/logs/access.%(project_name)s.log;
    error_log /home/%(user)s/logs/error.%(project_name)s.log;

    location / {

        proxy_pass_header Server;
        proxy_set_header Host $host;
        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Scheme $scheme;
        proxy_pass http://localhost:9500/;
    }
}

supervisor

[program:{project_name}]
command=/home/{user}/.virtualenvs/{project_name}/bin/python /home/{user}/{project_name}/manage.py run_gunicorn -c /home/{user}/{project_name}/gunicorn.conf.py
user={user}
autostart=true
autorestart=true
stdout_logfile = /home/{user}/logs/supervisor.{project_name}.log
redirect_stderr=true

Eu prefiro disparar vários processos individuais ouvindo em portas TCP diferentes e coloca-los como upstream no nginx... algo +/- parecido com isso aqui: http://justcramer.com/2013/06/27/serving-python-web-applications/

Mas como disse num comentário em seu commit no projeto que vc criou para hospedar essas configurações eu pretendo testar outra pilha de software: http://nathancahill.github.io/circus/