http://www.engadget.com/2009/03/17/live ... iew-event/
The Sims on iPhone...with customizable background music!
One thing that would be nice -apple squashed the idea today- is background apps. It's kinda lame that you have to exit apps (ie close them) to go to the springboard. Apple said the battery life would suffer too much. To that I say give us the option to buy and replace our own batteries at our whim and it's not your problem...jerks

And other things missing, like no video, that's rediculous
The big things-
cut. copy & paste finally people can stop asking

landscape email, notes & sms
mms MMS won't be available on the iPhone 1st gen. seriously apple...seriously disappointing, no wonder you try to outlaw jailbreaking, you can't figure out how to do it yourselves

multiplayer game support for things like FPS. Looks similar to the NDS but lets hope it supports connecting over WEP
It looks like the big changes in the sdk revolve around how the developers are now able to allow their apps to communicate over hardware add-ons. For example, a blood/glucose monitor that interfaces with the phone for diabetes patients (a little random and non-mainstream hmmmm?).