The second season hasn't aired on BBC America for stateside audiences yet (that's coming late next month; UK audiences saw all season 2 episodes already earlier this year)... no matter, BBC One controller Danny Cohen announced at the ongoing Edinburgh TV Festival (running this weekend) that a 3rd season of Luther, the critically acclaimed psychological crime drama starring one Idris Elba, has been ordered!
Season 2 reportedly outperformed season 1, on average, attracting over 5 million viewers and was well received by critics.
No word yet as to how many episodes season 3 will have, or when it will air, though I'd expect it'll be sometime in mid 2012.
Idris' next project will be Pacific Rim which is scheduled to begin principal photography in October; but, as of right now, he hasn't signed on to anything after that. So, he could very well go into Luther season 3 production shortly after that.
Idris has already expressed his desire for a big screen version of Luther. "The ultimate 'Luther' story will unfold on the big screen," he said in an interview a couple of months ago. Not sure if that'll ever happen; but at least what we can expect to see is a 3rd season.