probably but the devs never release anything public in betas, any way of doing it atm is not official
Just done some reading up. They haven't released it yet but they've got it to work on 4.3 (kind of) They've found a way to use the same greenpoison exploit to jailbreak 4.1, 4.2.1, and 4.3 even though apple has obviously closed it. It involves tricking the phone into thinking its on 4.1 by using 4.1 SHSH's before jailbreaking 4.2.1 or 4.3 firmware. I think it's what they are going to use for the next redsnow update to jailbreak 4.2.1 untethered. Hopefully it can be ported for a few firmwares yet and can only be stopped by hardware update like the shatter exploit. Clever stuff...
yeah i read that on muscle nerds twitter and he says being "green" using the same exploit so they dont have to worry about burning a hole or saying until next fw because its moot... and im sure from the first beta they look into jailbreaking and unlocking it but they dont want to waste holes on betas that most ppl dont even upgrade to...
by the time its released my bet it will either be 16th or 23rd of feb so they have lots of time