It was already known that Apple would shut the signing window once it released iOS 7. Those looking to downgrade iOS 6.1.3/6.1.4 are now out of luck as these firmwares are no longer being signed.
iOS 6.1.3/6.1.4 untethered jailbreak might be released in the near future, iH8sn0w recommends not updating to iOS 7
Later today Apple will release iOS 7 to the public. People who want to have the ability to jailbreak their devices are wondering what exactly they’re supposed to do. iH8sn0w, a popular figure in the jailbreak arena, recommends that they don’t update to iOS 7 right away.