Although the DevTem has not oficially announced the firmware 2.2.1 unlock, QuickPwn 2.2.1 is now available for download. Currently only available for Windows, QuickPwn will jailbreak the iPhone, iPhone 3G, and first-gen iPod touch running 2.2.1. However, those intending to unlock their iPhone 3G should not jailbreak with this method as upgrading with the stock 2.2.1 package will also upgrade the baseband (and lock the phone).
QuickPwn 2.2.1 is available for Windows. Download Now