Today, the Dev Team officially released GreenPois0n — two days after the anticipated 10/10/10 release was bunged up by geohot's competing jailbreaker, limera1n.
In an interesting twist of fate, the release announcement on Dev Team's blog includes the following: "Thanks to geohot for the bootrom USB exploit. We have opted to use that instead of SHAtter for the sake of exploit presevation."
The first release of GreenPois0n is Windows-only, and iOS 4.1 only. Those with an iPhone 4 and lower-version firmware should use TinyUmbrella to preserve their basebands. Otherwise, GreenPois0n supports iPhone 3GS/4, iPod Touches 3G/4G, and iPads, with Apple TV 2G and iTouch 2G support imminent.
Read our guide: How To: Jailbreak 4.1 Using GreenPois0n Guide