Microsoft is now accepting developer registrations for its 2011 Dream.Build.Play Challenge, an annual XNA development competition. The contest offers a total of $75,000 in prizes, with the first place winner taking $40,000 of that. All games submitted to the challenge must be created in XNA Game Studio 4.0, with qualifying games accepted between May 17 and June 14. However, intended entries must be registered before May 17. Prior winners included Lumi, Beat Hazard and Weapon of Choice, which have enjoyed prominent placement on the Xbox Live Indie Games channel. More details and entry requirements are available here.