Cablevision is developing a new PC to TV relay service which will provide a dedicated channel for customers to link up to their TV.
The data from your PC travels through Cablevision’s network where it is then sent back to the cable box and displayed on the TV via a secured channel.
Methods for using your TV to display computer content is already out there and it isn't all that hard to do but, I see this type of device/service useful for the "technically challenged".
(If you have family that always ask you to install/hook up new electronic devices, then you can see how this might work.)