Git is an extremely cool version control system, but a bit geeky to get used to it. For gnucash, it can be used to hold a local copy of the full svn repository, which means extremely fast version browsing. Also, it is possible to prepare your commits in your local repository first, and sending them to the gnucash svn server sometime later in a batch. Also extremely cool.
Note: You should install a git >= 1.5.0 because svn handling has improved considerably with these versions.
Here's how you as a developer get your local git repository (git-1.5.2):
git-svn clone -r16000:HEAD svn+ssh://USERNAME@svn.gnucash.org/repo/gnucash/trunk
Here's how you run the equivalent of "svn update":
Did I mention I think git is very cool?