No GPS
No 3G
No A2DP (can't listen to music via the bluetooth headphones)
No MMS (Can't send pictures to other phones)
No Flash support
No removable battery
No songs as ringtones
No direct iTunes access
No IM support
No voice dialing
No video recording
No thanks.
But hey, if you really can't wait, check out this neat iPhone simulator:
http://www.bram.us/2007/01/17/my-ismudginator-02/