This python script is the best I have come up with so far. I just hacked it together and on a cursory first couple uses, seems to be acting correctly, but I can\'t help but
I added this to my ~/.gitconfig file:
svn-status = !"git log `git svn log --show-commit --oneline --limit=1 | awk '{print $3}'`..HEAD --oneline"
which gives handy short messages if there are any changes that need dcommit, and shows nothing if you're up to date (assuming you've done a rebase or fetch). you could modify the params to the outer git-log if you like too.