Of course, I have not been able to use it yet, but not so sure that I will really be as impressed as the hoopla makes it seem that I should be.
You can watch the live launch broadcast in progress.
At the moment it looks like you can try it out at http://www.wolframalpha.com/input/
Update: 9:30pm Looks like they got this one blocked.
Eventually should be able to get on at http://www.wolframalpha.com.
Update: 9:40pm. Am able to get to the live site from Jefferson City at the moment.
Watch live video from Wolfram|Alpha on Justin.tv