According to the press release, "The new version ... includes the ability to create online, cross-platform multiplayer games for Xbox 360 and Windows using Xbox LIVE and Games for Windows - LIVE, respectively." We think that means cross-platforms games and multiplayer games, not cross-platform play for Xbox 360 owners wanting to duke it out with their Windows cohorts - sorry, folks, go ahead and add that to your wishlist of Studio 3.0 features. Matchmaking features, however, are integrated.
XNA Game Studio 2.0 "fully supports game development with all versions of the Microsoft Visual Studio product line." View the entire list of new features here.