MuscleNerd has brought some good news regarding untethered iOS 4.3.1 jailbreak.
He just confirmed that i0n1c's exploit successfully jailbroke Apple TV 2G but it still not able to jailbreak iPad 2.
MuscleNerd also confirmed that the new jailbreak will work for both Windows and Mac via Redsn0w and PwnageTool. You can reed between lines that the new jailbreak is very close to release.
For who asking about Comex's JailbreakMe, chpwn has confined that there is no new JailbreakMe after Apple patched Comex's userland exploit on the newly iOS 4.3.1, so don't trust such rumors.