A retailer listing suggests that Natsume is growing another Harvest Moon game for a spring sprouting on Nintendo's DS.
Silionera says Harvest Moon: Frantic Farming is set for a spring release, but it's uncertain which title is being localised, or if it's an all new title all together. It's likely to be Harvest Moon: Sparkling Sun and Companions released back in 2008 also for DS in Japan.