BSG borrowed the idea of having a coherent story arc, but they didn't plan it out ahead of time. Ronald D. Moore had a podcast of commentary tracks for each episode and openly admitted they were winging it the whole time. What BSG did right was to get all the small things right--get a bunch of really, really good actors, make everything look as naturalistic as possible, and let characterization rather than plotting or abstract concepts drive most of the storytelling.
