Comcast is not the only customer
I have had to disassemble at least one STB by at least one leading manufacturer to find the Atom based part inside. It was destined for someone else. Not Comcast.
By the way, it is a pity that neither the part nor the software load for it have made it into computers. It was doing very reasonable OpenGL, MPEG acceleration and so on. All the stuff which Atom + Intel video are supposedly not capable of.