As of now the XNA 3.0 Community Technology Preview is available for download.

XNA 3.0 CTP

This requires a version of Visual Studio 2008 and will co-exist with Visual Studio 2005 and XNA GS 2.0.

Note there is no Xbox360 support in the CTP release, however there will be with the final release, currently only PC and Zune.

Now I am off to see what else they added. :) Enjoy.