lets face it we are stuck with X86 for a very long time to come. Most businesses use Windows based machines and most of those will be Intel based machines. I know from a recent check on out Pc's at work that some are still using ol 478 CPU's - and because the software we use works there wont be any upgrades for some time.
Intel know this... there must countless number of old machines out there, and MS playing nicely with Intel will keep some form of backward compatability going for as long as physically possible.