Mario Party 9 should be coming - although Fortune Street (Itadaki Street) releases in Dec and is a bit like Mario Party. If you go on Walmart.com or Gamestop.com, Mario Party 9 shows up.
Wii in 2012 is still going to be a fairly big market for software. Wouldn't be surprised to see all this stuff in the West at all.
Dancing: Just Dance 4, Zumba 3, Just Dance Kids next and whatever spin offs Ubisoft, Majesco, Konami can come up with for the system.
Niche Core Games: No reason not to bring over Pandora's Tower, Xenoblade, Last Story to the US / Europe - games are done its almost free money for the couple 100,000 people who will buy each.
Japanese Content: Rhythm Heaven, Pokepark 2, Inazuma Eleven, Dragon Quest X .
Other Content: Mario Party 9, Madden, Call of Duty, etc
All that stuff plus a price cut to $100 is probably enough to keep Wii selling 100,000 per week for most of 2012 especially with various games from 2006-2011 still selling well (Just Dance 2-3, Zumba 1-2, Zelda, player's choice games, Wii Sports Resort, DKC, Mario Kart, Mario & Sonic, Kirby, etc)
Just Dance 3 though will largely indicate what kind of numbers Just Dance 4 will do next year when it can really stand out as the major Wii game late in the year.