In an interview with Fresh Air's David Bianculli, Friday Night Lights star Kyle Chandler confirmed that a third season of the Austin-filmed show is on. From Bianculli's blog:

. . . Chandler confirmed that a deal to spread costs and continue the series had been struck. All that was left, he said Wednesday, was to "dot the i's and cross the t's."

So the rumored DirecTV/NBC deal seems a pretty done thing; Chandler says he is planning to be back in Austin in June to start filming.