I'm sorry to sound like a jerk, but doesn't hooking up standard a/v cables kind of defeat the purpose of getting a Wii U in the first place since it is Nintendo's first true HD system? That is kind of like people spending thousands of dollars to have top of the line televisions, but opt out of getting an HD cable box. Kind of defeats the purpose in my opinion. Then again, if you're using the Wii to play original Wii games I suppose it doesn't matter what you have plugged in since to my knowledge the Wii U doesn't upscale older games.
C. Perry, Wii U comes with HDMI cables in the box. Component or composit will need to be purchased separately.
R. Cloyd, I always figure that a better source will display better on whatever monitor one chooses. Though composite can't push HD graphics, Wii U games will look better than Wii games because they are rendered at a much higher resolution. Of course, I'm running everything through HDMI these days, but if I weren't, I'd still prefer a higher resolution source.
Not to mention, Wii U is still going to be fun, even without an HD display. Like Nintendo says, it's all about the interface.