Yes.... I brought in some basic character that were rigged from TurboSquid - (Package:12-fantasy-character), then my friend (an animator) attached the a simple animation of walking and jumping to one model, and then I imported the model with the attached animation (He exported the animated models by FBX from Max).
Now to make it work I just tell it to run through frames 1-8 to walk or frames 9 to 15 to jump, etc etc.. Play around with bringing the character (from Poser or anywhere), importing FIRST into a 3D pacakge like MAX, Blender, MAYA, etc, then animating it (ideally the model should be rigged first), then exporting the rigged/animated model as an animation out of your 3D package as an FBX into Unity (it should import it as a prefab)... Play around with that process a few times until it works... Thats my suggestion.
As far a MoCap - I too am experimenting with that.. will try to post an answer if I can.