I can't talk for TDD, BDD, MDSD. But after working with git/hg on all my projects for half a year, I'd flat out refuse to work on anything that used SVN now.
Genuine interest: why? I felt the same, until I realized that I also want continuous integration, preferably as continuous as possible. This means that if my coworker works on a feature that somehow affects what I'm working on, I want to find out now, not in a week after he merges his feature branch.
If there's a single central repository anyway (continuous integration, remember), plus you want people to share with master/trunk/whatever after being under water for at most 2 days, the workflow when using git/hg becomes awfully much like the workflow that SVN enforces on you. When I realized that, I stopped investing time in converting my colleagues to git. I use git-svn myself so that I can stash, move files without `svn move`, do local commits, etc, and everybody is happy.
CI is a good argument for centralised source control, and like you say it is possible to get 90% of the benefits just using git-svn (I have done in the past).
The real power for me is the branching, especially shared branching.
My workflow is like this, each dev has their own github repo which is up to date with whatever is in their local repo.
So even if someone is working on esoteric weird crap, I can see it (ircbot telling you about commits) and I can pull it.
For CI we have a server that is also running a git repo of it's own. Anyone can push branches to it and they'll get put through CI.
So I can now take my branch, pull 3 or 4 peoples feature branches merge them locally then push to CI repo to see if anything is broken. If it is, I can fix some of it and push it back to whoever needs to know if there is something I don't understand.
