I, like many others, thought the Wii U was a terrible, terrible, dumb, dumb, bad name. Dumb.
However, I think I know why they named it Wii U; to capitalize on the recognition of the Wii's name by the casual audience. I think Nintendo realizes that the Wii was a fad to the casuals, and this is backed by the low attach rate. And thus we get similar branding and new gimmicks.
I really don't like this trend that's forming. I don't mind the motion controls, I think they're pretty cool. But how are you going to use the motion controls from Skyward Sword and implement new uses with the new controller for the Zelda Wii U at the same time? It looks like they're going to have to sacrifice one over the other. And I'd personally like for them to already have a control scheme down at the beginning of development to speed up development, which usually takes a long time for Zelda games.
I like the nameXBOX 360 despite not actually owning a Microsoft console. PlayStation was a good name and became very recognizable. It highlighted what gaming is about, playing on a specialized "station". I like the name PlayStation Vita too. I fully understood the name Wii and it grew on me.
But Wii U sucks. Plain and simple. I like the look of the console, the tablet has me interested but the name clearly sucks. And if you think it is a good name, I pity your children. What are you going to name them? --- "You are a failed abortion. Apparently, you could not even do that right!"