Updates: the entire cast has signed on, and apparently production has either already begun or has at least reached the "offices and parking spaces" stage, to quote the story published yesterday.
Plan currently calls for Netflix to distribute a 10-episode season in 2013 followed by a movie, though it doesn't say whether or not the movie is contingent on how well the season goes.
Still waiting for any word as to whether this will be available to folks who don't want to tithe to Netflix, i.e. a DVD/Blu-ray release later or broadcast, or availablity outside the US. (Netflix being available internationally doesn't mean the show will be. And as many people say regarding cable networks, not everyone can get nor wants Netflix.)
One of the sad things is Arrested Development missed out on capitalizing on things like the Housing Crisis and the recession; although I agree with the folks who posted earlier questioning whether revisiting AD is a good idea, you can't deny they're going to have a lot of story material to work with based on the stuff that's happened since it left the air.