Web Search Suggestions
Change image size in Mail messages
Bluetooth Keyboards
CallDAV invitations
Larger fonts for Mails, SMS & Alerts
Spell Check
Cell data only setting
Persistent Wi-Fi 
Rotate Photos (comes from the iPhoto and iPad OS)
Gift Apps (this feature already released on iTunes store)
Birthday Calendar 
Recent Web searches
Create Playlists
File & Delete Mail search results
Sync IMAP Notes
Top Hit in Search 
5x Digital Zoom
Nested Playlists
CardDAV
Tap to Focus Video (will not be supported for iPhone 2G/3G)
Uploaded workouts to Nike+ (will not be supported for iPhone 2G/3G)
Places in Photos (another iPhoto feature coded into the iPhone OS)
iPod Out 
Home Screen Wallpaper
Search SMS/MMS messages 
Wake on Wireless
iBooks (taken from the iPad)
Unified Mail App
New Dock on Homescreen 
Calculator App icon Updated
Multitasking (Does NOT support iPhone 2G, iPhone 3G, 1st Gen iPod Touch & 2nd Gen iPod Touch).