I watched the first episode and wasn't encouraged. It doesn't have the things that made Buffy worth watching: snappy dialogue, interesting characters, an interesting world, genre tweaking, insight into adolescence. That's a lot of baggage for a new show to have to carry, but at a minimum, I'd hope that at the end of the hour, I'd want to know more about Echo and who she is. I don't. And I'm not especially interested in the premise of the show, or even convinced that it makes all that much sense. (As opposed to teenagers fighting vampires. That's, like, totally logical. Duh.)
I'll watch another episode or two and see if it improves. But I'm not optimistic.