i dont think the hackers are even working on it. why the heck they cant release the failbreak to everyone.!!
Are you a hacker? How do you know this? Because they don't tweet every step they make?
And as already said, the failbreak cannot be released because it would be technically illegal to utilize let alone distribute. That said, it also could provide valuable insight into future 'legal' jailbreaks so they don't wanna throw away any potential exploits.