Where Has All the Science Fiction Gone?

As I was perusing the internet today looking to see when a favorite show of mine, Doctor Who, would be back for a seventh series, I was struck by an odd thought. With the end of Fringe in sight and a second season Falling Skies next month, I realized that was the full extent of the US science fiction I would be watching for the rest of the year. I was sadden to find that out, science fiction on US television has had some great runs; Quantum Leap, Stargate, Star Trek, and a number of smaller less well known shows.