Microsoft just launched Windows 8 last week and it's already getting sued over Live Tiles by an OS development company called Surfcast.
Surfcast claims that it already owns the rights to technology that does the same thing, naming in a lawsuit a patent for "presenting information from variety of sources on a display device" and a graphical user interface that "organises content from a variety of information sources into grid of tiles each of which can refresh its content independently of the others." For the record, Microsoft's Live Tiles patent is for "tile space user interface for mobile devices." It's kind of hard to see how the two are that different. Microsoft's patent is above. Surfcast's looks like this:
Though both companies clearly have patented the tech they're using, but Surfcast is saying that Microsoft's patent actually includes prior art. Microsoft has yet to comment on the suit, and we'll see if the claim has any legs.