What else to say, except go get it, and install on top of XNA 2.0. Don’t forget to install Visual Studio 2008 Express or the full version (which is free to our students).
I’m glad that they included an upgrade function from 2.0 to 3.0 beta. Its a shame that the new media functionality doesn’t seem to cover playing video on PC/XBox and I would love access to the 360 camera (are there ever going to be any games made for this?).