This is a question that I have been thinking about of a little while. I'm glad this article posed the question because it is hard to tell what television is and is going to be. Like the author mentions, television can be appointment based which represents what television used to be. Now we don't need to rush home to watch a television show because of it can be accessed through DVR, internet postings, etc. I think that television now is constituted by shows that are produced by a studio or organization that is intended to be aired on a broadcast or cable channel. These TV's shows are then completed in a way that fit what we still manage to have as the TV format, 30 - 60 minute episodes and commercials. As the medium of television is encroached upon by technology like Google TV, Hulu, iTunes, etc. it will inevitable change.
What will it change to? Jenkins talks about the use of video games, comics, web episodes, and more ways that people can engage with given television shows. This will definitely start to become more prominent as networks and studios compete to get their shows recognized, because as he mentions, "If it doesn't spread, it's dead", and this is more true than ever. It you don't get your material out there and people don't consume it, there's no way that people will be able to find your show with all the other material that are flying around on the internet, television, and game consoles.