Apple has pushed out the iOS 4.1 update as promised, if your running a iPhone 3G, iPhone 3GS, iPhone 4, iPod Touch 2G, iPod Touch 3G or iPod Touch 4G then the update is available for free to you now. It’s not a huge update but it fixes the iPhone 3G performance issues, Game Center is now activated and proximity sensor and bluetooth issues have been fixed for the iPhone 4.
As usual, if your a jailbreak user, or someone who relys on a hacked unlock then do not update yet until the iPhone Dev-Team give the go ahead. Make sure to backup your SHSH blobs whilst you still have the chance as well.
Sam's Blog 