It would surprise me a lot if the Wii U cost more than $399.99, and I think that the sweet spot is $249.99. Pricing really depends upon where the other console bundles (PS3 with Move and 360 with Kinect) are priced at the time the Wii U launches, because people who don't yet have a console are likely going to choose among the three offerings, and the biggest driver in the purchase decision is usually price.
I have repeatedly said I thought the next generation Wii should come out in 2009, then 2010, and when it was clear that it wasn't happening, have repeatedly said that a later launch was too late, as it will come too close to next generation launches from the other console manufacturers. Thus, the question now about whether the Wii U can compete with the PS4 and Xbox 720 is just a set up for me to say "I was right". I know how much all of the IndustryGamers readers like to acknowledge when I'm right, so thank you for a question that allows them to do so ;-)