They are "selected" programmes from Sky and the channels that are closely associated such as History, National Geographic, certain kids channels etc.

It's quite useful as a HD subscriber I always get the movie premieres in HD on the Thursday beofre they are aired and the first 2 episodes of lost 3-4 days beofre they went out.

The 80gig is not only for anytime, all TV you watch is cached onto this part of the disc to allow for the "instant rewind" and pause functions so even if anytime is turned off about 8-10 gig will still be needed for this function.