Bazaar 2.2 has been released recently. For those who don't know it: Bazaar is a very nice distributed revision control system, similar to git and mercurial. Where Bazaar really shines is the ease-of-use, good documentation and good interop with other VCS. Performance-wise, it's also pretty good and much faster than for instance Subversion on most operations. The UI is excellent, as there is a "canonical" UI provided by the developers, which uses Qt and looks the same on all supported platforms. This is really important for me, as I occasionally switch between Linux and Windows, and I really like the fact that I don't have to get used to different UI clients.
Bazaar 2.2 brings some nice performance improvements, especially the GUI starts up faster now. It works fine on 2.x repositories, unlike in the pre-2.0 times, the repository format is now fixed since quite some time, so there is no need to update.
Something totally different about Bazaar: Contributing to Bazaar is quite easy, unlike most other projects I tried. There's extensive documentation available, including a "contributing to Bazaar" guide. The developers are quite open, and you usually get useful answers from them. I found contributing to be easiest on Linux, on a typical Ubuntu setup you can get running in 20 minutes. For example, the contributions I've done were written on Ubuntu 10.04 running in a virtual machine.
If you're still using a centralized system like Subversion, it's time to try a distributed system like Bazaar now, as they have become a compelling alternative. If you never tried Bazaar because of FUD like slow, changing repository format, etc. -- you should definitely give Bazaar 2.2 a try. It's a really nice, polished and mature revision control system, and it's worth a look. Especially if you use Windows, Bazaar is a good alternative to git, as it treats Windows as a first-tier platform.