You'd be hard-pressed to do high-quality animation in Poser alone, but that said, most high-level animation uses a number of programs, not just one. I use Poser (with Daz figures) to edit bvh motion capture, and adjust & compose the animation, adding the hand gestures, applying lip sync (from Mimic) etc., then render in Cinema 4D. You can judge if it's getting me anywhere:

http://www.youtube.com/watch?v=UDq0_GOE0pc

Lots of other software gets involved, but I spend most of my time in Poser, animating. I think with the proper skills, one could do something decent using Poser in the process, that--while it wouldn't be a Pixar--I agree with Stallion that you might be able to make something good enough for television, or maybe some kind of online commercial product--at least, that's what I'm hoping, someday!  ;-)