I was expecting to chase some rattles, but there aren't any.  The only thing back there that I thought might make noise are the two vertical TV brackets that hold the TV in place (Frame comes with Sanus mount), but seems there's enough weight from the TV keep anything from moving.

There's a security panel in the equipment closet on the other side the of the wall and the door on the panel was rattling... I put some different screws in it which fixed the noise.