Unless and until someone else develops an app developer community on par with what apple has set up, nothing could convince me to leave the iphone. That's probably cries "fanboy" to some of you, but it's really not.
I'd say fully half of what I use my iphone for comes from 3rd party applications. I'm not about to give up Stanza (which is by itself reason enough for me to choose an iphone over anything else), iXpensit, Shazam, Air Sharing, mSecure, Pace, a host of great games, and many more because the Pre/Storm/G1/etc. has a nicer camera than the iphone (or whatever your feature of choice may be).
The app store is a game-changer. Apple hardly has to compete with Palm/RIM/HTC/etc. because they have thousands of private developers doing it for them.