Microsoft have announced they'll be opening up Xbox 360 development via a new set of development tools, XNA Game Studio Express:
During his keynote presentation today at Gamefest 2006, a Microsoft(R) game developer event hosted by Microsoft in Seattle, Chris Satchell, general manager of the Game Developer Group at Microsoft, announced details of the new technology, which will be broadly available this holiday season. XNA Game Studio Express will be available for free to anyone with a Windows(R) XP-based PC and will provide them with Microsoft's next-generation platform for game development. By joining a "creators club" for an annual subscription fee of $99 (U.S.), users will be able to build, test and share their games on Xbox 360(TM) and access a wealth of materials to help speed the game development progress. This represents the first significant opportunity for novice developers to make a console game without a significant investment in resources.
The full press release
has more information.
Pretty awesome news!@#!$