Have been experimenting with BazaarNG, a decentralized version control system. I find decentralized source control intriguing mainly I've been using CVS for so long that it's odd not to have a central coordinating server. Anyway, I've converted the bicyclerepairman CVS tree into a Bazaar branch using Tailor, so you could say I'm sort of committed now.
A benefit of decentralized version control is low barrier to entry - you don't need to setup and manage a central server, so getting something version controlled is just a case of doing 'bzr init' in the root directory of the project you want versioned. This creates a local branch - note that the working copy is the branch - there's no checking out of a seperate copy to develop on. Now I never got round to creating a subversion repo for my tagtriples stuff mainly because the overhead didn't seem worth it for a one man project. I suspect I would have created a bzr one from the word go and that would have had a number of advantages.
From an opensource perspective the interesting thing is that everyone effectively has their own branch by default. They can publish this branch on the web by just sticking it somewhere (e.g. using rsync to keep it up to date) and then merge and cherry pick updates from other branches trivially - the powerful decentralized tracking algorithms carefully track the provenance and history of each changeset.
The appealing thing about this for me is the ease at which people can join in project development. With CVS or Subversion the project maintainer must approve somebody and give them write access to the source repository for versioned development to happen. As a developer this usually requires creating some un-versioned patches here and there to prove your worth. With Bazaar you just create your own branch from somebody else's public one and away you go - do some versioned changes and then mail the maintainer pointing them at your branch.