An Italian site contacted Comex of Spirit and JailbreakMe fame to ask him about the release of his untethered jailbreak tool for iOS 4.2.1. His reply said alot in just a few words that is he is going to wait for Apple to release the iOS 4.3 update publicly.
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 sadly enough as Redsn0w 0.9.7 is the only way to get your device jailbroken untethered , which requires you to have SHSH blobs of iOS 4.2b3 saved. With comex being out of the deal till iOS4.3 is out, ther is no other way round. 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.