Sigh.
Do you all realize there have been dozens of trojans in the past five years for OS X? The point is that none of them spread as there are no mechanisms in the OS for silent and automatic infection. The Mac platform remains unplagued by viruses and trojans, but it has always been possible to infect your machine with something if you download it and run it yourself.
I can't wait until this meaningless hooplah blows over.