Ahh, I get that - the Farscape thing. I don't think Serenity was to get the fans to shut up at all, though; more like, Joss was going somewhere with Firefly, but it was cancelled before he had a chance to finish it. It wasn't even like Angel where he had time to wrap up all the plotlines really really quickly; they were filming The Message when they found it it was being cancelled, and that was it. And then Universal gave Joss a chance to finish the story he was trying to tell. So that was the feeling - from the series, it just stopped, there was no closure. Serenity was closure.