I think this is blown a little out of proportion... it's nothing more than the user opening too many windows for the system to cope with, and the OS runs out of resources.
Perhaps they should put a rate limit on the Windows + whatever keys, so that they only execute once until you physically press it again. Perhaps they should also not let any one program take all available resources from the system. But it's not really a bug or anything, and I guess once MS get round to doing something about this, they will rate-limit those keypresses somehow in a future windows update.
By the way, try it on XP, it works on there too, and nobody's exploited it yet!