A Federal lawsuit has been filed in U.S. District Court in Maine claiming Microsoft's Windows Phone Live Tiles infringe on four patents. The patents in question are held by SurfCast and the litigation involves Windows Phone 7, Windows Phone 7 and Windows 8 devices.
SurfCast is asking the Court to declare Microsoft directly and indirectly (through encouraging app development) guilty of infringing on their patents. The want Microsoft to be responsible for financial damages to SurfCast for this infringement. No injunctive relief has been requestion preventing Microsoft from continuing to produce, sell or distribute the involved systems.
Granted Microsoft has their own patent on Live Tiles and while the two patents may be similar, they may not rise to an infringement level. A Microsoft spokesperson commented that the company is "confident we will prove to the Court that these claims are without merit and that Microsoft has created a unique user experience."
Not sure where this one is headed but you can find the full Court filing here.