Within few minutes of release of iOS 5 final, MuscleNerd informed through his twitter account that the final build and iOS 5 GM are identical to each other. Therefore, it is possible to JailBreak even the final version with the updated version of Redsn0w. As always, this JailBreak remains tethered which means that you would again require to connect to PC/Mac every time your device reboots.
If you have not yet updated your iDevice to iOS 5, you can do restore to the latest firmware using iTunes 10.5. Unlockers should stay away from the update because it will upgrade your BaseBand. And those who unlocked using Gevey Sim should strictly ignore this software update. This is due to the fact that Apple has entirely killed Gevey Sim in iOS 5. So, there is no reason that your iPhone would still remain unlocked.
Just point out iOS 5 firmware in the tool. To JailBreak your iDevice, you can download the latest version of Redsn0w from here: Mac, Windows