There's confusion here between services being offered over IP and services offered via/from the Internet. Your access connection from $ISP, especially if it's DOCSIS or fiber, typically has more capacity than the bandwidth of the Internet connectivity they're selling you. It probably wouldn't be viable to offer you and everyone else that bandwidth to the Internet for business and technical reasons, but there is enough capacity between your house and $ISP's network to offer other services. As long as this doesn't affect your
Internet connection, it shouldn't be a problem.
Any impingement on your network connection then becomes a truth-in-advertising issue -- getting what you've paid for -- as has been taken up in the FCC's National Broadband Plan and elsewhere regarding companies that label their connections as "up to" N Mbps. Holding providers to their promises here seems like a more serious issue than being concerned about VZ offering crappy video-on-demand via a separate bandwidth pool.
I agree that it would be nice to have a big, dumb pipe to the Internet by which we can all choose the 3D video services we want, but that's going to require serious competition in access or some sort of public utility for access provision, neither of which seem likely in the US.