Level-5 makes games. Sometimes their titles don’t come to North America, sometimes they do. As for Studio Ghibili’s Ni no Kuni and the soccer RPG Inazuma Eleven, they will be coming coming stateside.
In an interview with Nintendo Power, Level-5’s CEO pretty much confirmed these title’s localizations. He didn’t give a specific date, but he did say “I don’t think it will that be long before you’re able to play these games.”
Level-5 may try to localize these titles themselves, but there is a chance they might turn to another publisher since their US branch is still small.
Also, The interview was in Nintendo Power, so whether or not it will just be the DS version or both the PS3 and DS version are unknown at the moment. I’m guessing they will both probably come over, but who knows.