Apple has updated the Apple TV to version 6.1, which adds a new way of hiding apps that is different from what I described in the book. I wrote a TidBITS article about the update, as well as the Remote 4.2 update, which adds controls for iTunes Radio and other purchased iTunes content. A previous Apple TV update, 6.0.2, fixed a critical security issue with SSL.
In other news, Apple has added a few more channels to the Apple TV: World Wrestling Entertainment; ACC Sports; and for our Swedish friends, TV4.
Also, Amazon has released an impressive competitor, Fire TV, which I described in a TidBITS article, Amazon Fire TV Turns Up the Heat on Apple TV.