From the SolidWorks Blog,

SolidWorks 2013 won’t be officially unveiled until September 10, but over the next few weeks, we’ll be giving you sneak peeks at a few of the new features we’ll be shipping this fall. And here’s the first.

In SolidWorks 2013, center of mass is a selectable entity in drawings, and you can reference it to create dimensions. In a drawing, you can create reference dimensions between center of mass points and geometric entities, such as points and edges.