Actually, the answer is simple; many existing apps will have a small black border around them, or they can be expanded with a little interpolation on the graphics. Developers can go back and upgrade the visible area of their app, but it's not as big of a limitation as you might think.
Many apps are probably ready to go with a larger screen, or need minor fixes. My news aggregation apps, there's no reason why they can't simply expand to accommodate a little extra space...
I'll be majorly disappointed if it doesn't have a 4" screen. I see my friends with their 4" Androids, and I'm jealous.
4G wireless would be nice to have, but I would probably leave it off most of the time to conserve battery life.
NFC ability would be nice to do credit card transactions with the iPhone.
I'm torn on whether to jump ship to Verizon on the iPhone 5. My office is a black hole as far as wireless, but they are setting up a Verizon repeater. But then I'd lose my...
Actually, I was pretty surprised that Jobs didn't announce streaming your own music collection. I thought for sure he was going to cap NAND memory at its current levels (or drop them slightly) and announce that iCloud streaming was the new way to listen to your music collection.
That may yet be in the cards; it may just be a licensing issue with th RIAA.
"HTC says Apple would rather sue than compete 'fairly in the market'"
Funny how some things never change. I seem to recall Franklin and Bell & Howell saying the same thing about Apple 30 years ago when they tried to sell their Apple ][ clones.