one thing that Nintendo left out about the Wii U is that it will have the ability to support 3D. The Wii U will offer support for connection to 3D televisions and support for developers to bring 3D titles to the Wii U platform. Given the hardware makeup of the system, 3D support is hardly a surprise.
Nintendo will apparently not be focusing on the 3D abilities of the Wii U. In addition, the company does not plan to emphasize bringing 3D titles to the platform. Nintendo’s reasoning for this is that currently the number of consumers that have 3D sets is still growing, but not growing at a pace that is enough for Nintendo to make this a core focus of the platform.
We also suspect that because the 3D support on the Wii platform would require the use of glasses (and Nintendo has been the company championing 3D without the need for glasses), it would seem odd if they changed gears in this direction with the Wii U. Look for third-party developers to be the ones to experiment with the 3D abilities of the Wii and to release at least the first 3D-capable games for the platform.
Read more here