Facebook Patent to Track Users Even When They are Not Logged In to Facebook
schneier.com
schneier.com
This is just another step in the privacy versus marketing arms race that started with simple things like cookies and web bugs. Those who care will block it and those who don't will become resellable data.
You can certainly make a case that this patent might cover those features but it depends on whether or not you want to put your tinfoil hat on.