Didn't think about the trademark thing. You're right, that wouldn't work.
I don't think including "Wii" in the name will be negative. The core base will buy the system based on the games, not the name. The only people who might have a problem are the mindless jocks who mainly play sports games and FPSs and tend to play while drunk/high.
Was making the Gamecube look like a purple purse a good idea? Sure you could say "well only idiots would be so superficial" but those idiots made a difference. Nintendo has been fighting an uphill battle to get anyone other than children and casuals to take them seriously for over ten years. Those little things count. Don't give anyone an excuse to ignore a Nintendo system. If there is a possibility of superficial people blowing the system off because its first impression suggests a casual system then it will happen. It must be avoided.
And it isn't like Nintendo will just win everyone over with the games. The Gamecube had some of the absolute best games on its generation and no one gave a ****. They didn't care about Metroid Prime or Pikmin 2 or Wind Waker. They just assumed it was same KIDTENDO system as the N64 and ignored it. Marketing is what gets people to pay attention to your system. Yes, smart people will know what the system offers and make an informed decision but most of the world are idiots. Those idiots can sink a product with a specific audience over the dumbest superficial nonsense.
I agree 100%. While I may not like the name (whatever it ends up being) I will most likely buy the system regardless. But I am not everyone. There were a lot of people who didn't buy the Gamecube just because it looked like a purple lunchbox like you said, and I myself deliberately went out of my way to get the cooler looking Platinum model which is the one which should have been default anyway. There is nothing wrong with the color purple or liking it, but its not a neutral color which can appeal to everyone. It also doesn't match anyone's living room setup, unless that someone is Pee Wee Herman or something. Purple is fine as an optional color, but the only colors any console should ever have as its default are black, grey, white, or silver/platinum. Anything else is going to stand out and clash.
So if the WiiU's name doesn't bother you and you are going to buy it anyway why should you care? I'll tell you why. It matters to you because if a lot of people avoid the system because of it, even though its a superficial reason, that could be all that developers like Rockstar need not to give us GTA V and similar games. The superficial image consumers who would reject the WiiU based on its name are the exact same gamers who would be buying those M rated hardcore games.
That's why the name matters even though its superficial and even though all of us here can look past that. Many other consumers out there can't look past that, and without them on board there won't be enough people buying Rockstar games so we can kiss that goodbye.