These come and go like the waves of the ocean, but this one has some actual merit. Most of these types of lawsuits are ridiculous and hardly make an impact, but this one just might affect gamers all across America. If the suit is carried out, Nintendo would no longer be able to sell the Wiimote in America.
Here's some links for you to read up on the situation:
Game Politics: "U.S. Firm Reports Nintendo to Feds in Wiimote Patent Dispute"
This one is particularly important; not only have they lodged a complaint against Nintendo, but they've also complained directly the the International Trade Commission.
GP: "Nintendo Wiimote Hit with New Patent Lawsuit"
Original news posting; a company called Hillcrest Labs claims that the Wiimote infringes on a product of theirs called The Loop.
Kotaku: "U.S. Internation Trade Commission Investigating Wii Patent Infringement Case"
Kotaku: "Nintendo Responds to Trade Commission Investigation"