In my years at Apple, the Caffe Macs chatter about Forstall was that he was the only legit successor to Jobs because he displayed a variety of Jobsian characteristics.
Comparing anyone to Steve Jobs is a tall order but Lopp does a good job in his most recent piece about innovation being a product of disruption and contention.
If Lopp is right, and Apple's slow (we're talking a decade here) decline begins with the departure of Forstall would Apple ever consider bringing him back if Apple needs help? Remember what happened to Jobs? He was fired. Then his company acquired by Apple. Then he became the CEO with the best "second act" in the history of business.
I dare Forstall to start a company named anotherStep.
/via John Gruber.