Yes you read that right ! An Italian site contacted Comex of Spirit and JailbreakMe fame to ask him about whether or not he is going to release his untethered jailbreak tool for iOS 4.2.1. Comex’s reply was swift and simple, à la Steve Jobs. He is going to wait for Apple to release the next firmware update to public before releasing his tool.

Just like Steve Job’s ones, I would like to really receive a short and direct answer to my question: your next tool will jailbreak ready for iOS 4.2.1 or the next iOS 4.3?

Comex replied:

Depends when 4.3 is out.

The email address of Comex as shown in the screenshot above seems authentic as he posted the same address publicly in a reply to a user on his Twitter account.
So as things stand now, the only way to get untethered jailbreak for iOS 4.2.1 is to use the latest version of Redsn0w 0.9.7, which requires you to have SHSH blobs of iOS 4.2b3 saved. There is currently no other way to get untethered jailbreak except for Redsn0w. If you don’t have SHSH blobs of iOS 4.2b3 saved, you can use Redsn0w 0.9.6 which can jailbreak (tethered only) all iOS devices on iOS 4.2.1.

Comex untethered jailbreak tool will be released only after Apple releases iOS 4.3 or 4.2.2, whichever they decide to before the major iOS 5.0 release in June this year.