Sure there is DRM, but damn it, Mac gamers have waited for this day for a long, long time! NOW is the time to show them that it was worth their energy to make this happen, open your wallets and buy as many Mac games via Steam as possible. If we don't, and the developers, after all this, still give up on Mac games, it will be our loss and the end of Mac gaming forever.
Well, if you were using Steam on Windows you were all ready dealing with onerous DRM...might as well use it on your Mac if it's that or don't play.