The internet is running rampant with speculation that Nintendo is working on a follow-up to its current home console, tentatively dubbed "Zii." Siliconera discovered a Japanese trademark for the Zii, and many wondered if this was the official name for the fabled Wii HD.
Conspiracy theorists will want to settle down, though. Our friends at Engadget discovered that the Zii trademark request is simply a renewal of a 2006 request. In fact, in addition to the Zii, Nintendo has applied for trademarks covering Bii, Cii, Oii, and Yii. Unless Nintendo is planning on making five new consoles, each with a different name, it seems as though the company is just covering its bases.
Source - What Is The Nintendo Zii? [Siliconera]
Source - Nintendo trademarks 'Zii' all over Japan [Engadget]