Ultrasn0w 1.2.5 adding 5.0.1 unlock support to be released later today
Just a bit ago, @MuscleNerd announced the released of Redsn0w 0.9.9b9 which adds 5.0.1 native compatibility as well as a bunch of new features. One footnote you may have missed is that later today(Monday) Ultrasn0w 1.2.5 will be released to add support for iOS 5.0.1. Until now you have had to use the Ultrasn0w 5.0.1 fix in order to unlock on that firmware, with this update of Ultrasn0w you will no longer need to do that.
To be clear, this does NOT add support for any new basebands, only compatibility with the 5.0.1 firmware for basebands which have already been deemed unlockable.