It has tools that will allow you transfer motion data between different models and different programs. You import a motion (several different types including BVH), apply it to a character bone structure (Dork, Mike, Vicki, Posette, etc) then I think you have some ability to tweak it and then you can export it (in several different formats, including BVH) to work with that character in Poser or other programs that can import motion data.

That's about as far as I understand it...I haven't touched BVH's in years. I don't own Lifeforms, so I couldn't tell you how well it actually works. To step up on my soapbox for a second, if you don't mind, I'd rather make movies that show off my animation skills than someone else's. I've personally found it's easier and more rewarding to keyframe animate my characters from scratch myself than deal with the frustrating task of tweaking pre-existing motion capture or walk designs.

Plus, if I'm creating sets and scenes specifically built to fit an animation someone else created or acted out, who's really directing this movie?

Okay, sorry... back off my soapbox.