Bad news this evening for anyone hoping to downgrade from iOS 7 to a lower firmware. It appears that Apple is no longer signing iOS 6.1.3 and 6.1.4 for a majority of its devices, effectively terminating their ability to downgrade.
This is significant for a few reasons. For one, folks who upgraded to iOS 7 and don't like the redesigned UI are now essentially stuck with it for the foreseeable future. And more importantly, word is a 6.1.3/4 jailbreak is coming...