So I've been working on improving the auto-rigging system that we used on Project Durian. Specifically I've been working to make it a lot more user-friendly.
Here are a couple of demo videos:
http://www.youtube.com/watch?v=eUSyoO2BmaQ (This demonstrates the easiest workflow.)
At the moment the code is not in Blender svn. It will be eventually, but not yet. I've also changed Rigify to be an addon, however, so you can try it out anyway. You can get the addon via bzr here:
Note that it only works with recent builds of blender (e.g. not 2.54)
Also, shameless plug: I'm available for freelance rigging and animation work. ;-)
Apparently bazaar is a bit too tricky for some. Here are zip files of the addon:
Revision 41: rigify_r_41.zip
Revision 45: rigify_r_45.zip
I've committed Rigify to Blender svn now. So the addon should automatically appear in builds from now on. You'll still have to enable the addon, of course.
Future updates will be through blender svn. I won't be maintaining the bazaar repository anymore.