Speaking with The Huffington Post about what to expect from the series, pilot director Joss Whedon joined the showrunners--his brother Jed and his wife Maurissa Tancharoen--to talk about the show's first season.
"One of the things that, you know, we've talked about just initially getting into it is, as you start it, you want to tell these self-contained stories," Jed Whedon said. "It's a little bit like the X-Files model: You can come each week and see [that episode] and not have seen everything, but if you have, it's a richer experience. And as we move forward, those things will start to weave together more and more. But we do want to always have every episode have its own beginning, middle and end, and feel like its own [thing]."
Of course, the degree to which The X-Files was self-contained after the first season or two is...debatable. But you see his point.