Despite the second Professor Layton title being out in Japan since November of 2007, the second title, Professor Layton and the Diabolical Box has only now received a release date for North America.
During the Q&A session following the Level-5 game design panel, someone asked president Akihiro Hino if we would see all six “Professor Layton” games released in North America and Europe. He said that he’d like all the games to come out in those territories, and that the company is working on the localizing the second title in the series, “Professor Layton and the Diabolical Box,” which he hopes it will be out in six months.
If you enjoy solving puzzles, meeting unique characters, and awesome accents then you should be excited for this sequel.

The third title was just released in Japan this past November. With any luck it won't take nearly as long to hit the shores of North America as its predecessors have.