The demo consisted of each providers' dedicated apps in the Samsung App menus. Selecting an app brought up a standard program guide grid (pictured), offering the full selection of each provider's lineup. Selecting a show from the grid caused it to begin playing live on the TV, just like you'd expect from a cable box.
We talked to a representative of Time Warner on-hand at the booth, who described his company's system a bit more thoroughly. It only works for Time Warner subscribers and requires a TWC cable box in the home, which communicates with the TV using DLNA standards. It doesn't directly allow DVR cababilities, but if you have a Home Media DVR it will control that, to play back recorded shows, for example. He also mentioned that future implementations might works for people who only have a TWC cable modem, and that DVR functions using a cloud-based live streaming system could also work.
He said the system would likely be ready to roll out on Samsung TVs before the end of 2011, and mentioned working with other providers, including Sony and Panasonic (Sony, for its part, announced a system that can access TWC's video-on-demand content, but not live TV, at its press conference yesterday). We assume the apps won't be free, since renting a cable box or cable card costs requires a monthly fee, but that information wasn't disclosed.