Google sure looks as one interesting piece of software. It is funny that you post the video now because I first heard of Wave yesterday, on TechCrunch.
I watched a part of the video (didn't like watching the whole hour and a half though) and the features in Wave are amazing. But I guess it won't be available before long (in a stable version) and I don't feel like dealing with all the bugs that will surely come with it. :P