Good news for folks who lost their jailbreak updating their iOS device to try out iOS 7, it appears that Apple is currently signing 6.0.x versions of iOS firmware. This means that you should be able to downgrade your iPhone or iPad to iOS 6 and re-jailbreak.
Well-known iOS hacker and jailbreak developer iH8sn0w was the first to spot the reopening of the signing window, and we have since had multiple users confirm to us that they have successfully downgraded and re-jailbroken their devices. More after the fold...