Serlet, is a pure (if you will) technical computer engineer... He get enjoyment about scientific computation, advanced algorithms, multi-threaded efficiency. The guy was nicknamed the "mad scientist" by Jobs himself, not because of his appearance, but because of he advanced studies in engineering and scientific computation.
He's like the man in the tech French community.
I can understand why he may want to leave, he's been gradually selling off his stock of Apple in recent years as well, so this makes sense.
Apple is more iOS then OS X and since Forstall heads the iOS development, there was no viable way Bertrand could have stayed on when Apple decided to merge the OS's.
I say it's a big loss for Apple. Though Craig should be a pleasant transition, and maybe a more frequent keynote speaker, since he's more understandable to the public.
Serlet will be missed. He's pretty much one of the Core brains behind OS X
I completed agree - except the part about being understandable. The ENTIRE audience got many of his jokes with Vista at the Leopard announcement and even with Snow Leopard. Just cause your ears cannot focus out the intricacies of a slight french accent doesn't mean the generic public cannot.