If the WiiU launches with Mario, Zelda or Metroid, you can forget any challenge between the next gen consoles. However, if there is a lack of first party support (which is unlikely) there'll be no WiiU Thunder.
Because every Nintendo system launches with Mario, Zelda, and Metroid? Even then, these franchises definitely don't make Nintendo systems "killer". If they did then the Gamecube wouldn't have had such piss poor sales since everyone raves over how strong their Mario, Zelda, and Metroid titles were.