This morning I managed to rig the Cream the Rabbit model I made and import it into Unity 3D to test with the mostly-automagical Mechanim rig/animation suite.
It was actually fairly painless. If you name the bones in your armature the same as they are in the Mechanim dialogue it automatically links everything up!
The only downsides I see, is that there is definitely some tweaking to be done around the weight painting in the model.
When the model initializes, her back juts way out because the arms are somehow linked to the back of her dress.
You can also see both eyes inexplicably bob up and down as she runs. Really strange! She’s also frowning which I believe is related to the default pose as well, despite her not having any bones (armature anchor points) directly related to the mouth.
All in all it seems pretty simple to set up, though.
You can play with a demo of the Cream the Rabbit Mechanim test here.