I wouldn't encourage anybody who bought one already to trade it in just yet. I'd tell them to have patience. I will get one after a price drop or closer to the release of games like Zelda and Smash. Even if the third party support isn't strong relative to the other systems, I think Nintendo's first party games are more than enough to keep most Wii U owners happy.
Playstation = The Beast from the East
Sony + Nintendo = WIN! PS3 + PSV + PS4 + Wii U + 3DS