I'll often jump into a git repo and forget whether it's pushing to other git repositories or an svn repo. It throws me off for a few seconds when I see 'origin is not a repository'.
It would be nice if git-svn repositories had some type of distinguisher. Maybe [svn:master] or different color set.
Take a look at this changeset/branch cromwellryan@329b818
It's specific to svn - so doesn't play well with plugging tfs in conventionally. I don't have a git tfs setup at the moment.