Well if you haven't read the homepage of this site, then you missed some great new's!!
Greenpois0n, from P0sixninja, chpwn and the rest of the chronic dev team is due to be released this sunday 10/10/10. This is an estimated time, but are hopig there will be no delay's whatsoever for release.

This jailbreak uses the SHAtter exploit, and Greenpois0n will only be available to iphone 4, ipad and ipod touch 4th gen user's. Everyone else will have to wait.
There is also no unlock for the 4.1 firmware yet. So if you require an unlock, then use Sn0wBreeze (windows) or wait for Pwnage Tool (mac).

So............roll on sunday. :D