I wonder how different this would be, in practice, to the typical on demand service. My take on it, being familiar with Verizon's fios on demand service, which has no excuses for bandwidth, is that it would be kind of a hassle to deal with and probably fairly unpopular compared to tivo-style devices.
All that being said, it's not a long leap from centralized DVRs to making television available on demand in general, and that is a move I would encourage, even if I did end up having to watch the commercials again.