Timothy Lee has a good piece explaining to those of us who already thought competition was dead in the cable industry that yes, it could get worse. The point is that cable is also a buyer, not just a seller. If Comcast and Time-Warner are allowed to merge they will have enormous market power as a buyer of both content and new technologies. This means that even if their merger does not directly affect the market for consumers (they mostly don't overlap in service areas) it will still mean significantly less competition and presumably innovation in the industry.