I've owned Nintendo consoles including; NES, SNES, N64, Gameboy, Game Cube, Wii and now the Wii U.
My experience didn't start off the best, the console worked ok... until I decided to complete the update which were available.
The update took approx. 1hr, the console supposably were to restart afterwards but unfortunately never did boot up again. To clarify - the blue LED light were on the console so there were obviously power but NO video.
Tried multiple HDMI ports and cables, power cycled the console for about 2mins - still no video.
I decided to try on another TV and issue still occurred.
A message on the Wii U Gamepad suggested that it could not connect to the console and to try turning the game pad off and moving closer to the console --- i'm not that stupid.
I decided to call Nintendo support, whom weren't really helpful - they didn't know what the blue LED meant on the front of the console - I would've thought they'd raise this issue to their Engineering group.
It appeared that the console were classed defective, or I would suggest it would be a bricked console after the update. The reseller decided to replace my console no questions asked and now I'm finally playing Black Ops II

If anyone else has experienced this issue, feel free to let me know!