Not sure how pissed off MS would be considering they own a nice big chunk of Apple. If anything MS would benefit from OSX on Intel as they would be less susceptible to critisim of anti-competitive practices.

TBH I think any Intel based OSX would start to suffer under the weight of trying to support the variety of devices.  If they specified too tight a spec then people would be put off IMO - MS might well be a bit of a pain but I'll take the low cost freedom of the PC platform over overpriced average performing Apple hardware any day (looks apart of course).