I suspect that most OSS projects will begin to migrate soon if they haven't already.
Git makes migration from SVN so easy there is very little reason not to do it, and with free web-based collaboration points. Given git-svn, you can still have SVN be a central storage point and still use git locally, so there is basically no downside to using it. It's hard to imagine how it wouldn't take over the OSS software world.
Hey, I'm just glad to get passed CVS and it's poopy recursive directory support.