MuscleNerd, member of the iPhone Dev team has just announced that they will release Ultrasn0w for iOS 5 after an update for MobileSubstrate is released tomorrow.
Dev team has already released Redsn0w for iOS 5 for Mac, which includes the PwnageTool functionality and iH8sn0w had released Snowbreeze for Windows that allows users to preserve iPhone’s baseband while upgrading to iOS 5.