Well, according to the Apple site, the new 2.1 update primarily includes :-

• Significantly better battery life for most users
• Faster loading and searching of contacts
• Improved accuracy of the 3G signal strength display
• Genius playlist creation (iTunes 8 required)
• Option to wipe all user data after ten failed passcode attempts
• Repeat alert up to two additional times for incoming text messages
• Improved text messaging performance
• Fixed bugs causing hangs and crashes for users with lots of third party applications
• Decrease in call setup failures and dropped calls
• Significantly reduced time to backup to iTunes
• Faster installation of third party applications
• Improved email reliability, notably retrieving email from POP,  Exchange push email

And still no cut and paste ! Third party app still required, dig around on this blog for a link to a good app for this.

And as you probably guessed already, ipwn tool can now jailbreak 2.1 !