Yeah, you're right, they can just download the 4.0 IPSW and restore it in iTunes, by Shift+Clicking restore and selecting the 4.0 IPSW. DFU mode may be necessary.
^^ this == win ^^
EDIT:
when/if they release a updated iphone 4 (reguarding the signal issue) they would probably hard-patch the exploit out of the system... or will try... thats what i would do...
You can only restore to 4.0 if you have your SHSH files backed up.
To clarify, you can only downgrade to 4.0 with SHSH blobs, but you can upgrade without them. So current iPad/iPhone/iPod Touch owners on 3.X firmwares will always be able to install 4.0 provided they can find a 4.0 IPSW. But people buying new phones with 4.0.1+ will NEVER be able to install 4.0 and make use of this exploit, unless someone finds a way to generate valid custom SHSH blobs, which would allow downgrading any device to any firmware, but thats unlikely.
QUOTE(overlord00 @ Aug 5 2010, 05:39 PM) QUOTE(jaxxster @ Aug 6 2010, 12:37 AM)