Keith Packard has been the one large spearheading the development of this next-generation Direct Rendering Infrastructure update that seeks to overcome some of the shortcomings of DRI2. For those unfamiliar with what this planned DRI update is about, see the earlier articles on the topic.
Keith has now provided an update on his blog about DRI3000. He's been working on private back buffers, hanlding window resize, splitting the XCB event stream, and other tasks. He has an early DRI3000 implementation working to the point it can handle OpenGL applications without losing any frames. This requires his experimental DRI3 branches of XCB protocol headers, the XCB library, DRI3 protocol headers, and the X.Org Server.
There's still some work ahead though before this next version of DRI is ready, so it might not be baked in time for the next X.Org Server release in around September of this year.