The iPhone Dev-Team has announced RedSn0w 0.9.15b1 which brings numerous new features including iOS 6 jailbreak for old devices, ability to restore to older firmware, manipulating SHSH blobs and etc.
iOS 6 jailbrak is tethered for iPhone 4, iPhone 3GS and iPod Touch 4G, untethered only for old iPhone 3GS with old bootrom. Tethered jailbreak means that each time you restart your device you will need to connect it to a computer and run redsn0w.
iPhone 4S, iPhone 5, iPad 2 and iPad 3 are not supported.
The iPhone Dev-Team released RedSn0w 0.9.14b1 that can perform a baseband downgrade from the iPad’s 06.15 baseband to 05.13 on the iPhone 3GS and iPhone 3G. The 06.15 baseband was used by many users to unlock their device. Now it is possible to to get back true GPS and an ultrasn0w unlock.
PwnageTool 5.1.1 allows to create custom firmware and preserve modem version for unlock with ultrasn0w or Gevey. PwnageTool 5.1.1 supports all A4 devices:
iPhone 3GS
iPhone 4
iPad 1
iPod Touch 3G
iPod Touch 4G
Apple TV 2G
You can download RedSn0w 0.9.12b1 here and PwnageTool 5.1.1 here.