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.
I'd like to think we've made enough progress that folks would no longer benefit from this, but I'm still open to it if anyone thinks it's a good idea today.