FWIW, I quite like both git and mercurial, both give me a better workflow than subversion for a lot of things I work on. Offline commits, local branches, and sane merging are *huge*. The approach to distributed repos is also very nice for folks who do want to maintain a fork elsewhere (forking isn't evil, it is a very good reaction to needing something slightly different which the majority (or the powerful) in the base project doesn't want).
Looking forward to trying svn 1.5 branch management, though :-) Being able to repeatedly merge from a branch I didn't branch from will be *huge* (ie, pull bug fixes from release branches without pulling cruft from trunk from whence I branched). I quite accept the practical side of saying "svn only" as long as no one steps up to manage git or mercurial. Saying "though shalt use svn because it is the blessed end-all" is BS. Subversion is great, and all, but it also sucks. Some things suck less for different workflows, some things suck more. For one-branch development, svn is awesome. Saying we can have only one "because" is very weak. Can anyone cite specific problems FreeBSD or Perl have had? -Brian