Pod2g and MuscleNerd, both iPhone hackers, have warned us to stay clear away from iOS 5.0.1. There is a code-signing bug that was uncovered a few days ago and it could make jailbreaking “dramatically easier.” Since Apple is aware of the issue and will most likely patch it in iOS 5.0.1, they both recommend that you do not update your device.
As of now, you will not be able to downgrade from 5.0.1 to 5.0, which is another reason not to update. I know the battery bug fix may be tempting and you may want to update but you have been warned.