Even ignoring the obvious problems with the study as described, it was likely to be a hoax just based on how pat the conclusion was and how it fed into the prejudices of those of us who must deal with IE6 on a daily basis.

It does make for an interesting study as a weaponised meme though; and it's exposure as a hoax is not likely to hobble it's effectiveness in spreading the idea that people who use IE are drooling idiots barely able to finger a computer. As a piece of agitprop it's quite effective, and although it's being called out as a hoax the velocity and intensity of the debunking is much less than that of the original.

I think I speak for more than a few of us if I say that it's veracity is completely irrelevant if it manages to embarrass a company director or two into decreeing upgrades. And it's a damn good prank.