There is already one update to add: NBC-Universal has been bought from its owners, GE (General Electric) by Comcast. They're buying a controlling 51% stake (leaving GE with 49% of the shares) for $30bn (thats £18bn) - though this creates such a large company that doubts have been raised as to whether it will be permitted.
See: Comcast to take control of NBC Universal
• Critics express concerns over monopoly and stifled creativity
Comcast-NBC Universal deal faces regulatory hurdle
Federal commissioner says tie-up faces 'a very steep climb' in effort to create powerful new force in American broadcasting