You all must be aware of the new up coming Greenpois0n RC5 Jailbreak tool which will be released by the Chronic-Devteam. At first it was now confirmed that which iDevices will it support. But it is now confirmed that the new Greenpois0n RC5 will support all the Generations which include iPhone4,iPhone3GS,iPod3G,iPod4,iPod2G MC Models. It will be an full untethered Jailbreak for the iDevices on the Firmware iOS4.2.1 and without the support for iOS4.2b3 SHSH and Firmware.
Below you can see the status of the Jailbreak tools and their support for the iDevices.
Apple has now closed the loophole which hackers have been using up until iOS 4.3. Basically Apple has ported ASLR into the new upcoming iOS which will be iOS4.3 and it will be difficult to Jailbreak it. But the Jailbreaking Teams are working on it.
So Greenpois0n will be launched really soon. It is said that it will be launched any day from now on. Once they have got some bugs fixed, they will release it. The release can be a day or hours.