Just finished watching the 13 available episodes of Defying Gravity. It's sad that the series got cancelled because it was just getting interesting. There are multiple possible reasons why it was cancelled and I don't believe for a second that one of them is that the show was not good enough. Sometimes a show just doesn't take off (I remember American Gothic, it was called "the best TV show that no one saw"). So, too bad for us Defying Gravity was cancelled, but even worse for true sci fi fans, Stargate Universe is not.
I like Stargate SG1, I completely fell for Stargate Atlantis (yes, even all the running in Canadian forests), and I was so excited when Stargate Universe started. What a letdown! Too much sex, not enough action, and no aliens! Sheeesh! Give a nerdy girl a break!
Unfortunately, a lot of people like more sex and no aliens. According to some sources on the web, SGU is actually the most popular SG show of them all. It sucks having taste that's so radically different from the bulk of the population but there you have it.
Actually, I've been thinking of writing a screenplay of my own sci fi TV show. The show would probably be somewhere between Star Trek Voyager and Farscape, as the main plot revolves around the science crew of a ship given the task of jumping from one galaxy to another and gather information about new life. The strength of such a show would be the incredible possibilities of exploring drastically new life forms and civilizations. The weakness would definitely be too little sex (at least as we know it). But, it's a work in progress - still gathering dust in my mind.