What is New?
A low level (DFU/iBoot/LLB) exploit is required to start the restoration of custom IPSWs. The past two jailbreaks (JailbreakMe & absinthe) for the A5 worked within iOS itself. These exploits are not capable of bringing the iDevice into a state where it will accept custom IPSWs. Therefore, an A5 device cannot currently downgrade to an iOS revision that Apple is no longer signing (even with SHSH blobs) and it cannot preserve the baseband when updating to a newer iOS revision.
Why is there no A5 support? :~(
While the future may always seem to get more narrower... Keep your head high and continue to be open minded.
Report any issues to iH8sn0w via Email (iH8sn0w@iH8sn0w.com) or Twitter (@iH8sn0w)