I think Sony fans are much worse now than the Nintendo fans at their low point.
It is understandable. PS2 was the undisputed champion. Then with PS3, it dropped down to third place. Anything that remotely gives it a chance to overtake the 360 worldwide is treated with frothing at the mouth enthusiasm, accompanied with frothing at the mouth trolling of the 360. The fact that it does have a chance to do that makes it even worse. GC fans wanted it to overtake PS2 but it had no serious shot and wasn't taken seriously or with the burning vitriol that is present in the PS3 fanboy set.
Nintendo fans are obnoxious but their fanboyism is more of a naive/childlike logic. Sony fans tend to be far more vicious than a Nintendo fan, whose worse attacks amount to little more than "you're a poopyhead." I have yet to see a Nintendo fan spam a major publisher's forum with tubgirl and pictures of maimed people like Sony fans did. Even worse, they did that only because of the suspicion that EA might have held pressured Sony into gimping a firmware feature. That is almost solid proof right there than Sony fans have proven themselves to be worse.
Nintendo fans haven't really changed much. They're still blind yes-men and think Iwata is the greatest business genius of all time with Blue Ocean Strategy being the best scheme of all time. The problem with them lies with the disconnect that publishers are releasing games on it that sell to that kind of demographic. They believe grandmas and soccer moms would buy Resident Evil 5. They're having a hard time understanding that because party/exercise games do so well on the system, that publishers are releasing more party/exercise games.
I don't know much about the Microsoft fans because again, I don't really follow their threads. I don't care much for Science Fiction, which means I don't care about Mass Effect, Halo, Shadow Complex, etc. So I don't get the complete picture.
I agree with Willco, its dumb to have console loyalty. Once my 360 breaks down and Microsoft refuses to repair it for free, I'm defecting to the Republic of Gamers. I don't really like how the future of console gaming involves waggling (Wiimote, Glowing Dildo) or gesticulating (Natal).