Eric Lippert engages in a paranoid fantasy: The Malware of Ultimate Destruction. I think he makes a good point here: our digital machines are vulnerable, and much worse stuff than Blaster can happen. But along the way he seems to believe the Microsoft marketing materials, at the same time that he proves their illogic.
In his ultimate worst nightmare scenario, he imagines a virus that replaces your operating system with a cleverly written emulator (emphasis his):
The net result: you are not even running Windows anymore so nothing is trustworthy. The emulator could be logging every keystroke, sending your files to Brazil, whatever the emulator writer wants. ... You don’t own that box anymore. The chain of trust has been broken.
This paragraph implies that the essential damage would be that Windows isn’t taking care of you any more, that your protecting white knight has been vanquished.
But later in the same post, he comments on the theft and posting of the Half Life source code:
... what seems likely is that attackers exploited a known vulnerability in Outlook, and a high-ranking Valve employee was vulnerable to the attack. The malware installed a key press logger, and from that point, it was pretty much game over, so to speak.
In other words, forget the baroque fantasy of an emulator taking Windows out of the picture and leaving you vulnerable. Windows (and Outlook) left you vulnerable in the first place!
I’m not Microsoft bashing here: I don’t think Windows is more vulnerable than other operating systems. I think Windows’ higher rate of attack and compromise is due to its higher market share and interest for virus-writers. But to pretend that Windows is somehow enforcing a pristine chain of trust is clearly absurd.