Season 4?

"In theory yes, but nothing is confirmed. It would not make sense to finish the series at the end of season 3. However I think it will be the final season. It should be as flamboyant as the other and end original and personal way. It is not perhaps kill everyone and leave things open properly. Must last season Braquo like no other discontinued."

- Jean-Hugues Anglade, February 14 (roughly translated)

I certainly hope so!
One of the best shows I've seen in quite a while (with the exception of perhaps Season 2)