Looks like Nintendo needs to remake another SNES or N64 classic...Oh wait, they are already doing that with Goldeneye and Donkey Kong Country Returns.
Seriously, Nintendo needs the new IP from Miyamoto within a year because I do not see the Wii magically going back to it's 2006 and 2007 numbers solely due to Kirby, Zelda Skyward Sword, DKCR, Goldeneye, and Other M.
You can only rehash the same stuff for so long and put another word on it's title before gamers start to question, why is your company hailed as the most innovative almost every year when all your big, exclusive releases are just the same old franchises in 3D with newer graphics?
Nintendo can afford to be complacent with the Wii for a year or more, especially with the Nintendo 3DS coming out in Spring 2011. After that, they should end the 7th generation by announcing a Wii successor in next year's or 2012's E3 for a holiday release in the Americas market.
The quicker Nintendo ends the 7th generation, the more they impact their biggest competitor, Sony, who wants the 7th generation to go on until 2014 to continue profiting off of what was a monetary black hole from 2006 until the price cuts.