From the Windows Live QnA team blog post entitled Welcome to the public beta for Qna.live.com! we learn
It’s
with great pleasure, a lot of late nights, and barrels of caffeine,
that our team launches the public Windows Live QnA beta.
For all you thousands of beta testers who took a chance on us, nagged us, mocked us, and made us better – we thank you. Keep doing it. Enjoy. Obey the code of conduct. We see you getting hooked.
The site is now available to all at http://qna.live.com/. Try it out and let the team know what you think.
Update: There is an interview with Betsy Aoki about Windows Live Qna on On10.net. If you look closely, you'll also notice a cameo by RSS Bandit.