This is the timeline that I want to follow in XCB development.
Prepare XCB and Xlib for integration into X.org
Freeze public API: Monday July 19th, 2004
I'm going over the XcbApi a final time with the hope of preparing it for a freeze. In an effort to pick an API that developers may be able to live with for a long time, the public API is losing things that may be useful but don't clearly have a good/lasting interface, such as a TCP-specific connection function.
Pass all of the X Test Suite: Monday August 9th, 2004
The X Test Suite is a comprehensive test suite for the conformance of Xlib implementations and X servers to the appropriate specifications. It can test a couple of extensions besides just the core protocol. It would be really nice if only it were completely replaced with something really nice.
The patches to Xlib that make it use XCB need to pass the tests in this suite, or the suite needs to be shown to be defective and a fixed version should pass the new Xlib. The latter applies to the protocol tests, for example, where LockDisplay/UnlockDisplay were omitted from all of the tests, causing most to fail immediately under the new code.
Commit to X.org: no date yet
At this point, the default would be to compile Xlib without XCB. Committing all of the necessary pieces to X.org makes it easier for new developers to turn on XCB support and try it out.
Document recommended replacements for Xlib components
Toolkits rely on parts of Xlib that XCB doesn't (and will never) provide, so I want to find well-designed replacements for each of those parts. I expect I won't have to write much code: this should be mostly a documentation project. X Input Methods support is an obvious example of something that applications need and that people have been working on replacing anyway.