Here's a look at some of the updates in this new firmware version:
• iTunes Wi-Fi Music Store
• Louder speakerphone and receiver volume
• Home Button double-click shortcut to phone favorites of music controls
• Space bar double-tap shortcut to intelligently insert period and space
• Mail attachments are viewable in portrait and landscape
• Stocks and cities in Stocks and Weather can be re-ordered
• Apple Bluetooth Headset battery status in the Status Bar
• Support for TV Out
• Preference to turn off EDGE/GPRS when roaming internationally
• New Passcode lock time intervals
• Adjustable alert volume
Don't try to install this update on an unlocked iPhone if you want to continue using it. Some people also report that some 3rd party software no longer works with this new update.