My guess is Nintendo will have a small price cut for Wii in Sept / Oct 2010. Probably $20-$30 / 20-30 Euros / 2000 -3000 Yen. If you look at the lineup for the Christmas / Holiday Season in 2010, Nintendo seems hellbent on making a killing with Wii software - its own and royalties - in the West. Not sure about Japan yet though.
Wii Party / DKC (at least based on the SNES games) / Kirby / Wii Relax (if it exists) are all potential million sellers in Japan. Each Donkey Kong Country provided a bump for SNES in Japan - even the third one. DKC Returns and Kirby should both be sizable bumps in Japan, and can be much bigger with a price cut for nostalgic SNES gamers. There will probably be a handfull of decent sized third party games that show up at the last minute as well.
Holiday Japan in 2009 was essentially this:
Core Bridge Casual
Samurai Warriors 3 NSMB Wii Wii Sports Resort
Pokepark Momotarou Wii Fit Plus
Tales of Graces Mario Kart Wii Taiko no Tatsujin
Price Cut ---------------------------------------------------------------->
For Holiday 2010 in Japan we know we have this roughly:
Core Bridge Casual
DKC Returns Kirby: Epic Yarn Wii Party
NSMB Wii Wii Fit Plus
Wii Sports Resort
Given the Wii attach rate is only about four, to tap all three types of player Nintendo really just needs a couple more big Core titles to be ok in Japan...the selection for Bridge gamers (who play core, bridge, and casual games) and Casual gamers (who play mostly casual and some bridge games) is already fairly solid.
In the West its more like this for 2009 / 2010 over Christmas.
2009 Core Bridge Casual
Modern Warfare NSMB Wii Wii Fit Plus
Lego Starwars Mario & Sonic Wii Sports Resort
Lego Indy Jones DJ Hero Just Dance
MK Wii EA Sports Active
Beattles: RB Monopoly
Band Hero Your Shape
Price Cut ------------------------------------------------------->
2010 Core Bridge Casual
Mario Galaxy 2 DKC Returns Wii Party
Sonic Colors NSMB Wii Wii Fit Plus
Goldeneye DJ Hero 2 Just Dance 2
Kirby NBA Jam NFL Training Camp
Metroid Mario Kart Wii Wii Sports Resort
Epic Mickey Michael Jackson Carnival Games 2
COD: Black Ops The Sims 3 Def Jam Rapstar
I think I'm on pretty safe ground in saying that the "Core" game lineup for the west is much stronger in Christmas 2010 than Christmas 2009, in terms of what will sell fairly well. The Bridge games look stronger too - The Sims / NBA Jam are both big in addition to DKC Returns. On the 'casual' side, Def Jam / NFL Training Camp seem like they could break out and Just Dance 2 / Carnival Games 2 should be popular with women / children respectively. Wii seems to have most of the major western genres covered with at least two games in 2010. Party, shooting, sports, platformers, dancing, and music are all covered with at least two fairly major titles. In 2009, you had really Fitness, NSMB, and sports as the only well-represented genres. Platformers, dancing, sports, and shooters should all see improvement over holiday 2009 on Wii in the west. In Others and the Americas, the Wii attach rate is about 8 games per user - and so as long as those users aren't looking for eight new games in one genre / category alone, there is more than enough product to induce alot of shopping for Wii software. Ubisoft (Michael Jackson, Just Dance 2), EA (NBA Jam, The Sims 3, NFL training camp), Sega (Sonic Colors), Disney (Epic Mickey) and Activision (Goldeneye, Call of Duty) should all have decent holidays on Wii in the west as compared to Christmas 2009 when not much really broke out (Just Dance is really a 2010 thing). So long as content continues to sell in major volume, the big publishers and Nintendo will continue to invest in Wii - at least in the West for another year or two.
So overall for Wii you can split 2009 vs. 2010 into this as far as I'm concerned roughly speaking:
HW
10' vs 09' Japan Americas Others
Q1 Up Down Flat
Q2 Up Up Down
Q3 Up Up Down
Q4 Down Down Down
SW Japan Americas Others
Q1 Up Down Down
Q2 Up Down Down
Q3 Down Down Down
Q4 Flat Up Up
In quarters with new skus / huge games / price cuts or whatever else, Wii will occassionally look bad in 2010 against PS3 / X360. But overall its really a fairly flat year, with HW likely down 10% and SW looking pretty flat. The growth in X360 / PS3 doesn't really seem to be hurting Wii, it is more that Wii already is owned by most 'active' gamers who want it, and so now it is penetrating less active users (who buy 1-3 games per year en-masse rather than 3-5 en masse as is still the case with X360 / PS3).
The biggest competitive advantage Wii has over PS3 and X360 is that even though the game libraries are very similar for PS3 & X360, Sony and Microsoft need different amounts of SW to justify maintaining their half of the HD market. When PS3 / X360 purchasing rates per user drop into the 2s, each company is fairly likely to bring on the next box - because unlike Wii, once purchasing rates get into the 1-2 games per year range I can't see either Microsoft or Sony being able to afford the declines. 1.4 games * 60m PS3 and 1.3 games * 62m X360s is a far worse outcome late in the generation than 1 game * 105m Wiis - given development costs and how large Nintendo's share of SW is on Wii vs. the Sony / Microsoft share of SW on PS3 / X360.