MuscleNerd from the iPhone Dev Team has confirmed that the unlock for iPhone 3GS and iPhone 3G (for all basebands) running on iOS 4.2.1 will be releasing this Sunday with an updated version of Ultrasn0w! But the unlock for iOS 4.2.1 on iPhone 4 will take a little long more.

iOS 4.2.1 Unlock

From  MuscleNerd’s Twitter Account:

Good progress today…everything is on track for updated ultrasn0w by Sunday/Funday at the latest (longer for iPhone4!)

Just wait till this Sunday! Stay tuned to Tips Needed for more iOS breaking news!