The jailbreak for iPhone 4, iPod Touch 4 and iPhone 3GS (new bootroom) on iOS 4.2.1 is tethered for the time being through the redsn0w jailbreak developed by the iPhone Dev Team. However these new devices are expecting a tethered jailbreak for the new firmware that should be available in time for Christmas.
The developer Comex is responsible for finding some new tweak to make the jailbreak tethered on the newer iOS devices. This will remove the need of jailbreaking our device each time it is restarted. The current jailbreak is already tethered for iPhone 3G, 3GS (old bootrom) and iPod Touch (earlier models).
According to a recent Tweet by MuscleNerd, the jailbreak is not as yet, but it could be expected by Christmas time. However he later removed his tweet that could mean a possible delay.
Stay in touch to catch the jailbreak news and procedures as soon as they are officially released.
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