So, Atlus has moved most of their inhouse Ips to the 3DS (Devil Survivor, Etrian Odyssey, Mainline SMT), SMT IV sold well on the 3DS (beating Nocturne´s fw without digital sales) and Nintendo seems to be supportive (30$ eShop credit for Fire Emblem and SMT IV, crossover)
....add the fact that Atlus apparently likes Remakes/Handheld ports (every Persona game, Soul Hackers, Devil Survivor)
Could you see an enhanced Nocturne port for the 3DS ?