Sublime Text X 20110110 is available now. Initially this was going to be a fit and finish release only, but I got a bit carried away.
I generally try not to release new versions too often, but I think it was worth it for this one.
The primary new feature is support for build systems. This works in a similar fashion to Sublime Text 1.x, but with a bit more flexibility, and the ability to detect the right build system for the current file. The .sublime-build files themselves are JSON now, too. The subprocess launching is taken care of via python, and makes use of the new output panel API.
The menu layout has been changed around, to make sure that more of the functionality is listed in the menu, and that the more interesting, multiple selection related, functionality is more prominent.
OSX and Linux platforms have also received some individual polish, with some OSX key binding issues being resolved, and the X11 selection buffer (aka middle click paste) being supported on Linux.
The full list of changes is at sublimetext.com/x.