Last year at E3, Nintendo showed off Professor Layton and the Mask of Miracle (the fifth Layton game) as part of its 3DS showcase -- without a word about Professor Layton and the Specter's Flute (Layton 4), leading fans (and, well, us) to fear that the company would pass over the last DS game in favor of getting that new 3D hotness into stores.
A North American trademark (number
85325626, if you want to see it yourself) found by Siliconera suggests that won't be the case. Level-5 filed a trademark for "Professor Layton and the Last Specter." Last year around the same time, Level-5 trademarkedProfessor Layton and the Unwound Future, which was then announced at E3 and released in September. So it seems likely Nintendo has at least one more game in store for the regular old DS this year!
Now, let's just hope London Life survives localization.