It makes sense that Forstall would be floated as a potential CEO since he's running the most important division at the company. Apple's iPhones, iPads, and iPod Touches contribute over ~70% of the company's sales.
There are two things that make us hesitant to believe Forstall will be CEO.
Steve Jobs was a divisive asshole, but he got away with it because he led the development of the Mac, the iMac, the iPod, iPhone and iPad. Forstall doesn't have the same résumé, so it's possible he won't be embraced in the same way.
He has "fraught" relationships with other executives including hardware boss Bob Mansfield, and design guru Jony Ive. Those three can't be in meetings together if Tim Cook isn't there to play peace-maker.
Former Apple software engineer Mike Lee calls Forstall "Apple's chief a-hole," but he means it as a "compliment." Lee says, "you could say the same thing about Steve Jobs."
Forstall is the driving force behind Apple's recent acquisitions including Siri, and Quattro.
The iOS team often misses Apple's Friday night "beer bashes" because they're coding.
Jon Rubinstein, who used to run the iPod business, clammed up and walked away when he was asked about Forstall at a party recently.
Forstall graduated high school with a perfect 4.0. He's married to his high-school sweetheart, who also got a 4.0 in high school.
He went to Stanford and join NeXT computers right out of school. When Apple bought NeXT he worked on user interface for the Mac, doing the "Aqua" design.
Forstall and a small team won a fierce internal competition to design iOS. Steve Jobs had the iPod division face off against the Mac division to design mobile software. The Mac division was stripping down Mac OS to make iOS. The iPod division was trying to improve its software. Forstall led the Mac group, and won. He was accused of poaching engineers and being secretive. After he won, Tony Fadell, who led the iPod group, left the company and Forstall is to blame, says BloombergBusinessWeek.
Forstall has a reputation as some who "manages up." He makes group achievements look like his own, and makes sure those around him know what he's accomplished.