Mac zealots will happily point out to you that it is not in fact a virus, it is a trojan, and that you have to be "stupid enough to install it". I swear some of them are stuck in the late 90's.
Personally I'd love for OSX to get slammed by a worm just to stem the flow of anal retentiveness coming out of Mac forums regarding malware. And yes, I own a Mac and have done for many years. I think a few outbreaks would do the platform good.