Well, if nothing else, there are the Microsoft weenies touting the expandability of their own gizmos. For most customers, it doesn't really matter, but for some it's a very big deal.

- The Crackberry addicts needs synchronization with MS Exchange. Maybe somebody could pull that off with some kind of IMAP proxy, but it would probably be a whole lot easier if Microsoft, itself, built a "native" email client. Probably not going to happen.

- The Gmail addicts want offline Gmail support (and not through Apple's Mail client).

- The VOIP people want Skype, iChat AV, or other things along those lines. I imagine AT&T isn't thrilled about this, but it's almost reasonable to imagine some kind of weird API that lets these apps do whatever they want over WiFi but restricts their access to the Internet over GSM.

- God help us, but somebody's going to want a BitTorrent client, at least until they discover just how much it slams their battery life.

- Gamers want games. Tons of games. All manner of games. Solitaire could be done as a variant on a JavaScript Widget. Not so much with multi-player games that want to use the WiFi to find "local" peers.

- Random people want offline Widgets, which could run just fine as mostly-offline JavaScript (just add some semi-reasonable persistent state). For example, I might want a currency converter for when I'm traveling.

- Somebody's going to go nuts with voice recognition and Bluetooth. Just leave the iPhone in your pocket and interact with it entirely using your voice. Read your email aloud, etc. Something like that clearly needs to run native and interface with everything.