Ive seen it once or twice in a game that disables the windows key the name of which escapes me at the moment, but yea no one needs a windows key its just another stupid microsoft gimmick.
alt tab for the win, you need to press two buttons at once so its much less likly that you will hit it by accident.
I've seen it that way as well. That's why i'd like to see it that way in AH. As for downloading a program (as suggested) to remap the KB, yeah it's possible and not all that difficult.
I'd be willing to bet that the majority of players on AH use the KB that came with their Win based PC. Disabling that button (in game only) would be of benefit to all who use these types of KB's. That would make their gameplay experience better by alleviating a common problem of accidentally touching it.
It serves a function that's already mapped to other keys, so my personal opinion is that we'd be better off without it.
Come to think of it, this should probably be in the Hardware section.