The 2.1 update is out.
The iPhone 2.1 software update contains many bug fixes and improvements. To get it, connect your iPhone to your computer using iTunes 8 and click Check for Update.
Update includes:
-Decrease in call set-up failures and dropped calls
-Significantly better battery life for most users
-Dramatically reduced time to backup to iTunes
-Improved email reliability, notably fetching email from POP and Exchange accounts
-Faster installation of 3rd party applications
-Fixed bugs causing hangs and crashes for users with lots of third party applications
-Improved performance in text messaging
-Faster loading and searching of contacts
-Improved accuracy of the 3G signal strength display
-Repeat alert up to two additional times for incoming text messages
-Option to wipe data after ten failed passcode attempts
-Genius playlist creation
Don't update until the iPhone Dev-Team releases an update to PwnageTool if you wanna keep unauthorized apps.