Because of the new release, all A4 devices are now jailbroken including the iPhone 3GS, iPhone 4, iPhone 4 CDMA, iPad 1, iPod touch 3G, and iPod touch 4G.
Following the release, the iPhone Dev Team and Chronic both released separate jailbreaks. The Dev Team has baked the jailbreak into the new RedSn0w 0.9.10 and the Chronic team has released an app in Cydia with the jailbreak called Corona Untether 5.0.1 if you are already using the tethered 5.0.1 solution. Anyone with a jailbroken iOS 5.0.1 is encouraged to download Corona.
If you aren't jailbroken, the best route is using RedSn0w, says the iPhone Dev Team, and to use the custom IPSW.
There are still no jailbreaks for A5 devices and all the above mentioned methods require iOS 5.0.1, not 5.0.0.
Written by: Andre Yoskowitz @ 27 Dec 2011 20:35