The jailbreak community has been active lately. Thanks to a surprise release of the limera1n jailbreak tool from Geohot, the release of Greenpois0n was delayed. Now both hacks use the same unpatchable bootrom exploit and are available to the iOS device-owning public.
In the meantime, the SHAtter exploit initially planned for Greenpois0n has been shelved for future use. Apple will surely fix the bootrom exploit in the next round of iOS hardware, however this time the jailbreak developers have a countermeasure ready for action.