The 3GS was an evolutionary product. If the Iphone5 is a revolutionary departure from what Apple has been doing (e.g. like the iPod was from Apple Computers), then who controls the company matters greatly.
It's very likely that without Jobs, the iPhone5 will be released with all kinds of little warts that a team under his guidance would have caught.
3G was also an evolutionary product, as was the 2G. The revolutionary products take a long time. Long enough for Jobs to take a vacation, come back, and they will still be working on it.
I thought he was taking a "medical leave of absense" and not a vacation.
It's possible that his condition is deteriorating, especially considering this is his second length leave of absence.
How long will the product development take---2 years? 3 years?
How long will Steve be out---a year? When he returns will he be at a 100% or will he likely leave for medical reasons again? For many people, this looks like the 'end of an era' with Steve Jobs.
It's very likely that without Jobs, the iPhone5 will be released with all kinds of little warts that a team under his guidance would have caught.