Nintendo of America, through their official Twitter account, have confirmed that Professor Layton and the Unwound Future, which was on the show floor during E3 2010, will be coming to North America on September 12.
Professor Layton and the Unwound Future is the third game in the series, which has Layton and Luke take a trip to London to see a new invention known as the Time Machine. Layton receives a letter that is from his apprentice, Luke Triton, ten years into the future. Events spur Layton and Luke's search for clues onto various mysteries, and they use the Time Machine to journey to Future London. There, they encounter the future Luke, where strange events occur and the team has to determine what is going on.
Nintendo of Europe has yet to officially confirm the game's release date but rumors are circling around October 2010, which would make sense considering the second game, Professor Layton and the Diabolical Box, was released about a month after the North American release as well.
Source: Twitter (NintendoofAmerica)