How could pod2g have an untethered 4S and dev teams still haven't released tools to achieve this at home?
The exploit I used to inject the untethering files to the 4S relies on having a developer account, and can't be released publicly. It's the same reason why @MuscleNerd has an iPad 2 tethered jailbreak but couldn't distribute it. So, we need to find a distributable exploit to remount the system partition read/write and to set Corona files at the correct places.
Why A4 version of Corona was easier to release?
Because a tethered jailbreak is a good way to install Corona!
Why don't you do a tethered jailbreak then?
A tethered jailbreak also relies on an exploitable vulnerability that we still haven't found yet!
In pod2g's final comment, he expresses his opinion about the impatience and ungratefulness of the jailbreak community with "pod2g, release this stuff quick, [your insult here], I've waited enough now". If you have already used the A4 untethered jailbreak for your iPad, or are expecting to take advantage of the A5 untethered after it is released...be sure to donate a few bucks to pod2g on his blog via PayPal like I have. Update your iPad 2 to iOS 5.0.1 to prepare the exploit being release to the jailbreak community.