Personally, it's not for me. I've used Yahoo Answers and other Q&A sites partially for their speed - I can post quickly and relatively quickly find out if anyone has an answer, and video slows down the process. It's much quicker to post text, and for others to respond with text. Of course, that ease means some people will post useless responses since they're not taking the time, but I'd much rather quickly scan text than sit through others' home movies.
I'm not the earliest adopter when it comes to video though. Maybe I'll be the last text blogger after everyone has moved to audio or video (though I see podcast creation and video blogging as media outlets that won't move beyond early adopters). Video Q&A may well work for certain types of questions.
Here's the other question: why use Jabbits and not YouTube? I know Jabbits is designed for Q&A and will reach a more targeted audience, but video responses are common on other video sites.