First off, I want to say that these are certainly fake but not for the reasons other people mentioned ...
With the hardware that is rumoured to be in the system it is likely that the environments in a game like Pikmin or Endless Ocean would appear to be very close to reality. Why I know that these images are fake is that the Pikmin image has way too little colour and the scale is completely wrong in the Endless ocean image; two mistakes that Nintendo is far too careful to make. After all, does anyone think that Nintendo would create game environments that were predominantly redish-brown or a realistic diver game where the diver is the size of a barbie doll?