A new Harvest Moon game is in development for release sometime this year in Japan.  Take a look:

The Harvest Moon series has been building a strong reputation up over the years, especially on Nintendo formats and as a result Marvelous Interactive is bringing canother exclusive, this time to Wii. Going by the roughly translated name of ‘Harvest Moon: Tree of Tranquility’ (thanks to creamsugar for the translation), the game has yet to be given a firm date for release, but is still on track for 2007.

Tree of Tranquility looks interesting from the scans.  Hit the link for more screens and info about this Wii exclusive:

Source: Cubed3