I have got BattleForge running under OS X but it isn't very playable.
The patching won't work in OS X, but I have also Windows installed and I installed BattleForge to the same folder as in Windows and got it to launch by patching in Windows. But the game has too many problems to be really playable. The most annoying problem is that I can't get my keyboard to work at all so I can't type anything in the chat or use the hotkeys. Also, for some reason the chat window is in my way when I try to create a new game.