Also, some of the websites are about games that were discontinued (New Super Mario Bros. Mii) or games that were not yet announced (like Wii U Sports or Wii Party U).
http://mariobrosu.com
http://supermariobrosu.com
http://newsupermariobrosu.com
http://supermariobrosmii.com
http://newsupermariobrosmii.com
http://supermario4.com
http://miiverse.com
http://MiiWaraWara.com
http://WiiUProController.com
http://wii-u.com
http://wii-u.net
http://wiibalanceboardu.com
http://wiifitu.com
http://wiimusicu.com
http://wiipartyu.com
http://wiiplayu.com
http://wiispeaku.com
http://wiisportsu.com
http://wiiubalanceboard.com
http://wiiufit.com
http://wiiumusic.com
http://wiiuparty.com
http://wiiuplay.com
http://wiiuspeak.com
http://wiiusports.com
http://wiiuware.com
http://wiiuwheel.com
http://wiiuzapper.com
http://wiiwareu.com
http://wiiwheelu.com
http://WiiUFitMeter.com
http://WiiUPanoramaView.com
If you find any others I missed, post them here!
Updates:
http://gameandwario.com
http://wiizapperu.com
BREAKING NEWS!
Nintendo just put up the WIi U page at http://www.nintendo.com/wiiu
Edited by NinjaU, 30 June 2012 - 04:29 PM.