Wii U will support 3D TVs
Nintendo console will potentially work with your 3D TV, but the company's not making that a requirement for third-party devs.
While 3DS games are always going to have some degree of 3D in them (hence the name of the system), Nintendo seems to realize that the technology is still just a fad for regular TV owners. According to an article on Joystiq, "the Wii U will support 3D televisions but Nintendo itself won't be focusing on making 3D games."
While the fact that the Wii U will support the tech at all seems to be more of a concession to hardcore, technology early-adopters, it does show Nintendo's willingness to give third-party developers the room to create the kinds of experiences they want. Still, whether the 3D effect is hands-free or not, I still feel it never adds anything meaningful to the experience. Once life-sized hologram games start coming out, then I might jump on the 3D bandwagon.