iOS 4.3 can't be too far off, and we still don't have an untethered jailbreak for iOS 4.2. (4.2.1, to be exact). Those who have been holding off on the update may be disappointed to know that it's still not available. The good news? We are still hearing constant progress updates, and it seems that it is moving along.
In a recent tweet, hacker Pod2g, said of the GreenPois0n the following about the GreenPois0n untethered jailbreak:
"The good point is that because of this (and the fact that Apple fixed the kernel exploit in 4.3), we‚Äôre all working back on releasing gp."
So they are definitely working on releasing the new jailbreak. Then there is the fact that he mentioned of Apple fixing the kernel exploit in iOS 4.3.
We saw a video about a week back, so we know it's working minus a few minor bugs.
Certain devices can run the jailbreak untethered, we have more details at the following links in case you are interested: