The question might be, who is willing to pay more than they even do at TSMC. Apple is certainly one of them. And Apple, while competition, is not in a direct competition.
Apple likes their margins as much as, if not more, than Intel itself & so neither Apple nor Qualcomm is going to their biggest competitor's fabs anytime soon. Actually Intel opening up their fabs proves one of two things ~
a) They realize how hard it's getting to keep their tick-tock cycle in place & also seeing how they've had yield issues with their 14nm Intel now wants to fund their node shrinks with a little help from their competition in the mobile space. The biggest obstacle for them however is that the top three in the mobile/tablet arena really do not need Intel at all & this is because ~
1) Apple is shifting towards TSMC gradually, away from SAMSUNG for obvious reasons, so I doubt Intel would ever make the Apple custom SoC as cheap as TSMC or even SAMSUNG & then there's rumors flying around that GF could supplement SAMSUNG in their chip making endeavor for Apple.
2) Qualcomm fabs their chips at TSMC & SAMSUNG, correct me if I'm wrong here, so I doubt they'll need Intel anytime soon seeing how both of these foundries are in top gear for their next round of node shrinks, plus Intel being their biggest potential competitor in the mobile/tablet arena would make it that much hard for'em to justify the shift.
3) SAMSUNG doesn't need Intel at this point in time & potentially could rival them in the fab biz as they have the knowledge & money to pull this off, the only mega conglomerate aside from IBM that can do so in the not so distant future.
b) The revenues from their mobile division are barely trickling in atm & it could be that their internal projections are somewhat pessimistic so they'd like to open up other potential avenues for growing their top & bottom lines. Again I don't see how any of the major chipmakers will go to Intel in the near future unless they're pretty desperate for volumes & are willing to take a hit to their margins in the process!
The reason I've highlighted these points is because a while ago, on a similar thread, nearly everyone agreed that Intel would "never enable their competitors come what may" so that just got me thinking that either Intel has assessed the tough times ahead are worse than they originally thought or they're just trying to make a quick buck. Either way, depending on the response they get, Intel is still kinda desperate(seeing how their core PC biz is tanking) & seemingly they wanna diversify, only this time with conviction.