It's impossible for Natal and Move to pressure Nintendo into producing higher quality content. Nintendo is already giving their games 100%. No one can give more than 100%. By definition, that is the most anyone can give.
Now, if you want to talk about third party efforts on the Wii, I doubt it. The uncertainty of motion control schemes, combined with the high development cost of HD games, has a great chance of rendering Move and Natal support a non-starter, as the Wii has already shown that motion control alone is too great a risk to take for AAA games.
Super World Cup Fighter II: Championship 2010 Edition








