Nintendo usually announces new handheld hardware earlier in the year. Feb-March release dates. I think it's so they don't ruin holiday soles for their older hardware. I always found it strange the people don't get upset about it, because if little Johnny gets a 3ds in December and the new 3ds XL comes out in February (like it did in the west)... But I don't think there has ever been any real backlash to it.