I agree, there is no magical knob that the carriers turn to get more bandwidth. With current standards it gets very expensive as you have to lay down either more copper or more fiber. The point being MediaG3 has the technology to provide the wireless speeds we all dream about but without the huge coat associated with it.
Laying more cable? I believe fiber is the transport of choice these days and there is plenty to be had. At&t went to rated plans due such large concentrations of users in large metro areas such as NY city. Also as I have said many times, getting users through the carrier network is one thing, getting them on the Internet is another, and that is usually the choke point. MDGC has no solution for that.