Git's avalanche
Which means to topple Subversion, you have to bring a new paradigm to the table. The plethora of distributed version control systems seem to be that next paradigm. But it's not purely equitably "better", it's different. Better in many regards for many purposes, but not just better. Like SVN just felt better, period, than CVS.
So given all that, I think the Git move is even more interesting. That camp is competing not only to convince people that a new paradigm is appropriate for many things, but also as that it, one-out-of-many, should be the one to embody it.