According to Videogamer.com and according to an source at a publisher, Nintendo will be debuting a new hardware platform at the Game Developers Conference this year. According from an anonymous source:

“Just heard a rumour that you may be interested in: Nintendo are going to announce a new platform at GDC. Some devs have already started work on it.”

Could it be Wii 2, Wii HD or DS2?

Source: Siliconera