Wii has
Monster Hunter G, Final Fantasy: CC Echoes of Time, and this other game with an S which should be pretty big through April in Japan. Release dates beyond that are basically TBA, but you figure Punch Out or Wii Sports Resort makes it by the end of June.
Sales will probably down from Week 1-26 2008 in Japan. Toward the end of the year, when Monster Hunter 3, Pikmin 3/Zelda or a Tales, or one of the new Nintendo IPs like Cosmic Walker arrive, sales should become comparable or above 2008 levels. If that doesn't happen, Nintendo can always drop the price of Wii by 50,000 Yen.
Dragon Quest IX on DS could also have a bit of an echo effect for Wii in March (since Wii is getting DQX) as people who are DQ fans switch back from Sony platforms to Nintendo platforms.
For the Americas...
Nintendo seems to just be sitting on Disaster: Day of Crisis. Mad World, The Conduit, Punch Out, Wii Sports Resort, more music games, more Sonic, the TMNT fighter are all possible for the first half. Wii sales are so good though that Nintendo has basically left quarter one open to third parties except for the Game Cube remakes.
I'd wager sales will be up throughout the year in the Americas, almost regardless of what they do.
For Others...
Same deal...Sonic. Music games. Mad World. Wii Sports Resort. Punch Out. A few other supporting titles. Thats probably enough to keep sales steady or up slightly in the first 26 weeks.
People are difficult to govern because they have too much knowledge.
When there are more laws, there are more criminals.
- Lao Tzu