The next step in all of this may turn into having our regular television networks turning into TV on demand. You have a listing of shows to pick from and through your box you can d/l a certain number of shows that you wish to watch with commercials included. You can already do it via the internet so why not just make it available from your cable box as well.
Advertisers are already trying to find ways to shape the ads you watch by changing the way the cable box works. If they had their way we would have commercials based on our age/sex/location and they are also trying to find ways to see what you buy and then send ads your way based on your purchasing trends.