[quote=Leotamer]
Also I would pose the question that can shapeshifters, at least dedicated shapeshifters, even be petrified. Couldn't they just shape-change back?
[/quote]

I do believe that they can. It's the entire being that is petrified, not just the skin. That includes brain, muscles, organs, etc... Try to think of it like... time suddenly stops for you and for you only, At least that's how I envision the gorgon's petrifying stare to be.