Although Rockstar is working very hard on Max Payne 3 and GTA V, they could work on L.A. Noire in the future.
Based on the answer to a question of a fan, Rockstar didn’t ruled out a possible sequel of the popular L.A. Noire.
No confirmation yet, just a question and answer:
Hey R* is there gonna be something more about L.A. Noire?
While there won’t be any more DLC or additional content for the current release of L.A. Noire (we’re all too busy working on Max Payne 3, GTAV and other games to come), don’t count out the possibility of a new game in the L.A. Noire franchise in the future. We simply have not decided anything. We’re all very pleased with how that game turned out and are considering what the future may hold for L.A. Noire as a series. We don’t always rush to make sequels, but that does not mean we won’t get to them eventually – see Max and Red Dead for evidence of that – we have so many games we want to make and the issue is always one of bandwidth and timing.