I don't know if it's a regular thing, but I was scrolling through the guide a weekend or two ago and saw them airing a marathon on BET. Might want to look out for that again -- if you're like me and sometimes have trouble hearing British accents, if you watch it on BET, you'll probably be able to put captions on, which STILL isn't possible on a Netflix TV interface. (I did an awful lot of rewinding when I streamed Luther.)
I was home with a cold (boo) and just finished Series 2. OMG - this might be one of the most challenging shows that I've seen. Incredible tension, horrifically realistic scenarios of graphic violence, compelling and flawed characters, just a big bowl of yikes...
...in a very good way. It's like the movie Se7en was turned into a television series. I think that the new two 2-parter season format works well - the overall narrative and direction of the show feels a lot tighter, proving that less can sometimes be more.
Did you know that there's a novel as well? Have to pick up a copy...
I'm hooked after the first 20 minutes.