Now, however, things have changed. Not only has iPhoneSimFree found a way to unlock the existing iPhone firmware once again, but also a method to restore bricked phones. The new unlock should work with any updated units:
Further to this, we are very proud to announce, (after some very difficult and lengthy hardware hackery), we were able to retrieve the necessary info to create the world first 1.1.1 unlock solution. We have now tested SimFree v1.6 with phones that have the new Baseband version 04.01.13_G with full success.
They also post instructions on how to recover your iPhone if it was damaged or bricked by the update, which might save you an RMA if you haven't sent it in already. Hopefully, the team will keep it up as time goes on and Apple releases more updates.