As promised pod2g posted an update on his current jailbreaking progress and it looks like an untethered iPhone 4S jailbreak could be right around the corner. The A5 cache issue has been resolved and pod2g has received assistance from fellow iPhone hacker Saurik. Here is what pod2g wrote on his blog:
"OK, figured it out, the A5 cache is not a problem anymore. I sorted it out by doing the untether in a single thread and by flushing all the dcache then all the icache in a row at a strategical point of the process. It took me like a hundred of tests to find the key. Hard for the nerves."
" I discussed with @saurik today about the launchd boot process, and he's found one missing piece of the puzzle I needed to have a perfectly stable jailbreak. He's definitly one of the best iOS gurus out there. Thank you saurik!"
Originally an untethered iPhone 4S jailbreak seemed unlikely, but recent progress by pod2g and the iPhone DevTeam has been promising. In October, MuscleNerd tweeted a picture of a jailbroken iPhone 4S, but said there was a lot of work to do before it could be released to the public. It looks like both pod2g and the iPhone DevTeam are close to cracking the current holy grail of jailbreaking. Keep your fingers crossed.