Notably, XNA Game Studio 2.0 adds support for Xbox Live and its counterpart Games for Windows Live. Microsoft claims that many online features, such as matchmaking, can be seamlessly integrated into XNA games. The new version of the software also includes updates to graphics, math, connectivity, audio, and Xbox 360 Guide interface functionality, and Microsoft offers a utility to convert existing projects to the 2.0 format.
In addition to the version announcement, Microsoft said it will launch a new Dream-Build-Play development contest, open to creators of XNA-based games. Finalists will each receive a $3,000 stipend, present their games at San Francisco's Game Developers Conference 2008 in February, and potentially be interviewed for an internship at Microsoft's UK development studios Rare, Lionhead, and Microsoft Research Cambridge.
According to the announcement, signups begin this Friday, though the official contest site states they begin on December 20.
The announcement also indicates XNA Game Studio 2.0 is available from its official site, though the site does not yet appear to have been uploaded, currently offering only the original XNA Game Studio express and a note that the 2.0 Beta has ended.