The same people who do the I'm a PC campaign. You know, the one that has a bunch of paid actors all saying "I'm a PC" but doesn't show any machines doing anything.
I think MS missed the mark on that campaign. I wanted them to go for the throat and poke fun at the perceived smugness/hipster attitude of Mac owners. Instead they took the high road ... disappointing.
What's particularly interesting is Apple don't really do the smugness stuff (anymore). If you see the new iPhone ads, it's all iPhone, on screen, doing stuff. MS have enormous potential here, they could just show PCs running games for example, the PC has loads more games than OSX, they win that one hands down. Instead they come off as looking like a poor imitation.