Professor Layton and the Curious Village sales were decent in North America, great in Japan, and phenomenal in Europe.
This sales chart shows how Professor Layton and the Curious Village sold in all three territories. Level 5 published the title in Japan and Nintendo took care of the rest of the world. Out of all regions Professor Layton sold the most in Europe and it was released in PAL territories last.
Satoru Iwata, President and CEO of Nintendo, says the surge in sales may be due to the different box art. Professor Layton and the Curious Village looks like a brain training game in Europe.
Notice that Nintendo of America adapted the box art for Professor Layton and the Diabolical Box to showcase some of the puzzles. Perhaps, that will help the sequel sell better here. At any rate the huge spike in European sales guarantees every Professor Layton on the Nintendo DS will get a Western release… eventually.