[msbarnett]

I can't see Apple buying AMD; like in the G4/G5 days, they'd just have to get up on stage every year and acknowledge the large performance gap between themselves and Intel and insist that it would be reduced sometime in the upcoming year. (Edit: And as a sibling post points out, this isn't even practicable. Without an x86 license they'd be dead in the water).

On the other hand I could see them buying NVidia and taking control of their GPU woes directly. Intel Integrated graphics aren't going to stop sucking, and OS X isn't going to stop growing its dependency on a real GPU anytime soon.