Do not buy a Wii U expecting the true next generation. When Xbox 360 and PS3 upgrade, Wii U will again be in the Wii's position, a little bit behind. If major AAA releases with huge budgets are your thing, buy yourself an Xbox 360, and buy whatever they come out with next, it's pretty well a given that Microsoft will put its giant bags of money where its mouth is and cater to these games.
Buy a Wii U because of Nintendo's lineup of first party titles, and what you expect third parties to try on the system - desipte the lack of mulitplatform, the Wii did get some great games designed specifically for the hardware, even from big publishers. If ZombiU is any indication, the same will be true of the Wii U.