YouView will bring a new free-to-air internet-connected TV service to UK homes in 2011 called "Project Canvas". YouView set top boxes will be subscription free, and with an Internet connection will allow users to watch digital TV shows from BBC, ITV, Channel 4 and 5 and SeeSaw via their respective online catch-up services, all within one user interface. Also an option to watch HD programs and buy "pay TV" programmes and films will be avilable.
YouView will be an "open environment" and would allow content providers, device manufacturers and application developers to create [their] add-on TV features".
Other features include the ability to record live TV, browse TV guide (past, present and future) and search for programs and actors. The website describes the service as "brilliantly simple, and simply brilliant. YouView will be everything TV should be".
More Info: YouView