Valve's Jason Holtman and Doug Lombardi recently sat down with GamesIndustry.biz to discuss their big release of Steam on the Mac, and not only do they reiterate that great stat that games released on the Mac see a nice bump in sales, but they say that the best days of Mac gaming are yet to come. They can't share numbers yet on just how many Mac vs. PC players there are (though they say the response has been great, and you can see Mac players in games often), but Holtman and Lombardi both say that from small game developers to big game publishers, Steam on Mac has helped everyone see just how active and important the Mac gaming scene is. There are international users on Macs, and the amount of player interest in games for the platform has made developers rethink their old plans of releasing a Mac port when they get to it rather than day and date with the PC title.
That is, in a word, awesome. And Lombardi says now that publishers are interested in the platform as whole, we'll see some "different types of experiment on pricing and promotion and all that stuff on Mac titles," as companies try to figure out how to make the most of this market they've been neglecting for so long.
Valve has already said that bringing Steam to the Mac was the most significant decision they've made with the service, but I'd argue that even this early in the process (even Valve admits that it doesn't have a lot of data yet on how people use the two platforms), it was a seismic event for Mac gaming as well.