Nico Mak (the original developer of WinZip - and remember PKWare was the DOS market leader) was making $1m+ off of WinZip licenses...10+ years ago - as for now...I'd say easily order of magnitude.
Some highlights from the liveblogs:
It's like a Mobile Wii - TouchFighter - use accelerometer to tilt and navigate (remember Wing Commander?)
Will Wright's Spore on an iPhone!
70% of revenue goes to developer, paid monthly. $99 if you want to sell, $0 if you want to give away (most app developers will probably do both)
Deploying to iPhone from the SDK is simple - take that control-freak mobile network operators from the control-freak Apple!
Enterprise-class Wi-Fi, with WPA2/802.1x,
I like how Apple ignores pressure and takes time to get things ready and right. If there was an SDK 6 months ago, it probably would not have been such that non-Mac development orgs could code something in 2 weeks (with Apple assistance)