Would we be seeing Ultrabooks if Apple had not considered AMD?

When Intel first announced that it'll be funding PC manufacturers to compete with the MacBook Air, the rumour at the time was Apple is considering moving the MacBook Air to the Ax architecture at some point (in a year or two). Intel, for its part, was protecting their marketshare and helping others compete with the MacBook Air even though it produced the processor for the MacBook Air.

Last week we heard that in actuality, Apple had an AMD version of the MacBook Air but changed plans last-minute to go back to Intel. The natural conclusion can be reached that if not for this move, Intel would not have helped fund the competition, and Ultrabooks would still be a rarity in the PC market. 

I wonder if Apple had just stayed loyal to Intel, if long-term, they'd be better of.