Ive just watched the Event video, really its the push notifications, the apis and the accesory intergration that are really impressive. Well more so the apps that are being developed from the new SDK.
http://events.apple.com.edgesuite.net/0903lajkszg/event/index.htmlExample a Heart Monitor that plugs into the 30pin connector, this also works with bluetooth and wifi with standard protocols or custom protocols, which I guess means A2DP is finally here! Hardware vendors, FM transmitors, Stereo docks can develop their own app to work with the hardware.
The push notifictation is the answer/alternative to running backround processes, all third party servers would submit their notification/update through apple, which makes sense with apps such as ESPN doing over 50K updates a month.
It;s a pleasant update.