But of course going forward the vast majority of Mac users are going to be getting their software through the Mac App Store, and not downloading random programs

But of course going forward the vast majority of Mac users are going to be getting their software through the Mac App Store, and not downloading random programs off the internet. That plus the default GateKeeper config (that prevents unsigned code from being installed) will dramatically reduce the risk of the average user getting hit by trojans on the Mac platform.