There is a total of FIVE Harvest Moon games that have yet to come out in North America or Europe. We got Island of Happiness, Tree of Tranquility, Rune Factory 2, Run Factory Frontier and Shining Sun and Friends. Yet, Marvelous seems to be taking this Harvest Moon 10th anniversary business seriously and ANOTHER Wii Harvest Moon was unveiled in Famitsu.
The title has yet to be 100% Translated, but a rough one seems to be Harvest Moon: Wonderful Animal March. I can't read Japanese but I'm going to guess this game is to Tree of Tranquility as to what Shining Sun and Friends is to Island of Happiness. If you don't know what I'm talking about SS&F is an updated version of the DS title IoH. So I'm not entirely sure this is a whole new game.
But it is quite obvious, update or not that Marvelous liked the art style in Tree of Tranquility being that it returns in this title. That along with some seemingly redesigned main characters is what makes me speculate that this is an updated Tree of Tranquility. But obviously with the roughly translated title, the game is going to have a lot to do with animals. Sheep Cows and Chickens? PSH. I'm talking about Elephants, Lions, Giraffe, and Zebras! Man I wonder how much good quality Lion milk is going to sell for in the game?!