As a dad to two young boys, I can see tablets being huge hits in the family market. Being able to read books, watch movies, play games, listen to music whereever you are, in whatever room, in the car, etc is a very valuable option.
We don't watch much live TV in my house so we wouldn't need TV shows but an ultra portable device that is dead simple to use that can provide a wide variety of entertainment would be useful in many circumstances. It is a want to have, not a need to have, but it would be cheaper and better than things like built-in displays in the car, dedicated tiny video game systems, etc.