
However they are not going to release the updated version of UltraSn0w until iOS 4.3 has been released and rumors of them only releasing ultrasn0w only two weeks after.

Expected date of the iOS 4.3 release is March 11th, so there's a very big chance we will be able to unlock our iPhones from March 11th onwards. iOS 4.2.1 can already be jailbroken, but with higher basebands, it cannot be unlocked yet.