Ah, I see now you say CURRENTLY. Got it. Well there are CURRENTLY no viruses (per your definition) attacking a fully update-to-date Windows box.
We just had a different frame of reference. I thought you were saying Windows sucked because exploits existed on unpatched boxes, but Max was great because a fully patched box hasn't been exploited via a self-replicating virus. I guess your unequal comparison through me off trying to get you to compare apples to apples (see my very first post). But now I see you are actually comparing apples and oranges, so I guess I agree with your comparison.
A fully patched Mac is a lot more secure than an unpatched windows box.
But I guess you run a big risk the first time you try to patch OS X (if you have a build that is vulnerable to the phantom update).
Why would that be? The problem would only exist if the user had installed and run the trojan program... and why would they download and install the trojan, masquerading as a "security patch" from any place except Apple's secure site using Software Update from the Apple menu? If the trojan has not been installed, then it is perfectly safe. No risk at all...
Nor or there any computer viruses that have infected Apple Macintosh OSX in the past.