Here’s what we’ve got so far:

iTunes Wi-Fi Music Store has been added
Louder speakerphone and receiver volume (reported by some but not most)
Home Button double-click has been added like the Touch – which works even if the phone is “locked” so you don’t have to use the slider to get to iPod functions
Space bar double-tap shortcut to put in a period and a space (w00t!)
Mail attachments are now viewable in portrait and landscape
Support for TV Out is there
Preference to turn off EDGE/GPRS when roaming internationally (another w00t!)
Adjustable alert volume

New SMS alert choices

NOTE:
Does not appear to destroy your phone if you’ve jail broken or unlocked. Your phone will be in jail again after the update (AppTapp reportedly no longer working) and the sim lock is back in effect. iNdependence is also a no go.