I don't see why not. I just discovered it today, after seeing this thread, and I'd say, if you did, it would make sense to have options like arenamate.net to view US or EU seperately or both simultaeously.
The real question is why wouldn't all the world's 19 tw1nks be included together?
Certainly many think of themselves of "best" in the world at playing a low level character in WoW, not in just a region.