Indeed, the fourth instalment in the Professor Layton series is coming to Europe later this year, on the Nintendo DS. Along with the localisation, it will also come with a new name. Professor Layton and the Spectre's Call is the new title for European versions.
The game is the first in a trilogy of prequels taking place before Professor Layton and the Curious Village. To clarify, it's a bit like Star Wars in terms of how the story is structured. Professor Layton and the Spectre's Call tells the story of how the Professor meets Luke and how he becomes his apprentice. Along the way you can expect new and challenging puzzles.