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From experience I've seen that teases of new games don't really do much to spur sales.
Actual game releases or price drops do, not "well look at these games we have coming six months from now".
Super Mario 3D Land and Mario Kart 7 were unveiled months beforehand for example and didn't help 3DS sales.
Showing more on next year's lineup couldn't hurt, but I don't think it will actually have much tangible impact on sales.
They need a game that actually is releasing in the 1st half of 2013 to drive sales, not the promise of future games.
I also think it's a far bigger question to ask "what content does Nintendo have upcoming that appeals to non-Nintendo fans for Wii U?".
They either need to make headway with casuals (so Wii Fit U has to be a blockbuster and can't go the way of Nintendogs + cats and Oni Training on 3DS, where those trends fizzled out) or with non-Nintendo core players (so Rayman or The Wonderful 101 needs to be a blockbuster hit bringing in non-Nintendo fans). Otherwise, they are headed for GameCube-Land .... a system supported mostly by Nintendo enthusiasts and ignored by everyone else.
