I'd like to see them try to take DVR use away from people that have been using them for years. I saw a figure somewhere on this site stating that over 40% of households in the US have at least one DVR now. There would be an incredible backlash of they tried that. Many people barely watch any live tv anymore. If they won't let us DVR their programs until a more convenient time for us we probably won't watch them anymore.
They don't have to just make DVRs go away, you know. They could always make it to where you can't fast forward through commercials.