i'm no XP fanboy, but for the sake of fairness, it should be pointed out that they specifically installed XP with no service packs, didnt run any updates (which MS pretty much forces you to do), and didnt have it behind a router/firewall (which the vast majority of users now do). it was a pretty flawed experiment in my opinion. of course an out of date OS with no protection will get hit.
granted, i still think OS X would do much better in the same circumstances, its not a real relevant or telling experiment that they setup by a long shot.
the part that gets me is that you have to be a power-user of sorts at this point to NOT get automatic updates, and yet any power user would know how to secure the machine, so it isnt even the "old ladies who dont know what they are doing are prone to attacks" argument. there is no person who would actually run the machine like this.
anyway, like i said, i am no XP fanboy, but it needed to be said. biased research pisses me off, especially when it is so blatant that it was obviously set up to fail.