I don't think anything, especially not a hardware design or name change, would change the 'Nintendo is kiddy' crap.
Anyone with half a brain knows that Nintendo isn't just for kids, but it doesn't stop the other half from using that lie to knock Nintendo or people who game on Nintendo machines. They don't have any real facts to back up their hate/bashing/trolling of Nintendo, so they revert back to "Nintendo is kiddy!!!111" whenever needed. I don't think anything will ever change it because it's been going on far too long and the people who say it aren't smart enough to come up with anything else.
I'm not a huge fan of the name Wii U, though, but it has grown on me after using it so much since last E3. I don't know what I would want them to call it, but I know I groaned when they announced the name on stage last year. As for the look of the system and controller...I guess I don't mind it. I'm always for even more sleek and sexiness, though, so I wouldn't mind if they changed up the aesthetics a bit, either.