On our podcast it has been a topic of discussion as to what the plural of Wii is. Reader Xmorbius sent in this very question to Nintendo of America, and obtained a response from Customer Service Rep Sue Page. Read her explanation below, click the scan if you would like to see that portion of the original document.

In your letter, you asked what the plural of Wii is. Hmmm? You would say for example "two Wii systems." The emphasis of the plural would be on systems and not Wii.

Well that answers that question! I still say the plural of Wii is Wii...I just like the sound of that!