I don't think there is any coincidence that Blizzard games are as successful as they are AND happen to support both windows and mac. There are a lot more people than the arrogant PC users think that use mac or were forced to use mac growing up because their family owned it for this reason or that. Speaking from my own experience, I was given Starcraft and Diablo 1 for christmas because they were the only games that would work on the computer my parents owned at the time. Since then I have been loyal to Blizzard because of this fact. Making a game accessible to a wider range of platforms is simply logical as it makes it more accessible to more gamers. Do it.

I don't think there is a coincidence that WoW is as popular as it is AND just so happens to support both windows and mac. Do it, Star Wars, do it.