You love NBA and MLB but you haven’t yet updated your Apple TV 2 to iOS 4.3.1 because you love XBMC, Hulu, Couch Surfer, Plex and Remote HD even more? The waiting is over and you can now have it all as iPhone Dev-Team has released untethered iOS 4.3.1 jailbreak for all iDevices (except iPad 2). Just update your tiny black box to 4.3.1 (Apple TV 4.2.1) and then re-jailbreak it with the freshly released PwnageTool 4.3. Note that PwnageTool is Mac only, Windows users will have to wait until redsn0w is updated to support atv2.
Update: sn0wbreeze, a custom IPSW creator and jailbreaking tool for Windows has also been updated to version 2.5 which can now jailbreak your Apple TV 2 on iOS 4.3.1.