Placing the Wii U upright isn't the problem, Nintendo even gives you stands for the Wii U to be placed upright, if you bought the deluxe bundle.

It's blinking red because you are blocking the air vents.

If thats the case then Nintendo should get rid of them on future Wii U packages. My WiiConnect24 was constantly on as well, it also fried my gpu but not to the point where i can't play it, it just left black dots all of the screen.

Even if it gets fried you got your warranty so no worries there.

1 - Unplug its power cable from the wall.

The flashing red light means that either the GamePad's battery is critically low or the console itself is overheating

Automatic updates. If you DL to your HDD drive the light will turn orange and the HDD will flash. So obviously you have something on your Wii U only that is updating. The Wii U can also auto update patches for games you own too while its off. The Wii U auto updates and installs while its off.

"Nintendo don't give me sum boo shit"

I don't get it, my wii u came with a stand and I place it upright, and this has never happened to me before. I think this happened because the system looks crammed and just needs more air.

flashing red means overheating (i think) although sometimes it freezes instead

This actually just happened to my Wii U yesterday while I was playing SSBB. It happened 2 more times after that. So I called Nintendo and I've only had my Wii U for about 5 months now, and I have my warranty so they'll fix it for me for free. This really sucks though.

I've got a Wii U that doing this and the red light on mine doesn't go away when I unplug the unit, wait, and plug it back in.

it's the red light of death

The system is not designed to be place upright.

I found me fix :) I took out the battery, I never put It back in and my wiiu works.