As you can read on the XNA Team Blog the first CTP (kinda early beta/alpha) for XNA Game Studio 3.0 is available for download now.
The major new features beside full VS 2008 (Express, Standard, Pro, etc., but not longer VS 2005) support you can now write and deploy games for the Zune. Luckily for me I own one (not many non-US people do since the Zune is ONLY available in the US). Please note that while the Zune is a powerful device it obviously will NOT support any advanced rendering techniques at all, but all the other parts of the XNA Framework are supported very well. This means 3D games or shader based games will be possible on the Zune and the display is just 320x240 pixel and there are other things you have to think about (controls and playing music), but other than that it should be pretty easy to start developing Zune games right away :)

While the new features are really cool and I definitely will check out the Zune development options (XNA MVPs already saw some cool samples and stuff at the MVP Summit about this ^^), the show stopper for me is the "no 64 bit support" issue. All my PCs (work, home, laptop and even the servers) run on 64 bit vista/win2003/win2008, it will not be easy to play around with XNA 3.0 ("Hey, go away from that PC, I wanna test something").

Anyway, check out XNA Game Studio 3.0, especially if you own a Zune and find this Zune-targeted game development cool. Other features worth checking out are better sound APIs in the new Media namespace, namely the SoundEffect and MediaPlayer APIs. They allow you to play sounds and music much easier and in more formats (yeah, mp3s).