The likeliness of a sim marketed for a mac has the same likeliness of a sim marketed for linux (ubuntu and similar linux based OSs). Lets face it: have you looked around the last time you were at an Apple store? There's only a handful of notable games. EA, one of the largest game manufacturer, has maybe 5 games marketed on the Mac platform and that is probably a high estimate.

If you upgrade to OS X 10.5 Leopard, it comes with bootcamp and the windows drivers are on the disk. if you never downloaded boot camp beta, you'll never see it unless you upgrade to leopard. even if you do use bootcamp, you still need a legit keycode for XP so you can get all the updates.

An RC sim for Mac won't be out for a LONG time so don't hold your breath.