However, just to say..
I like Castle. It is kind of ordinary, and seeing Nathan Fillion following up Captain Hammer and Malcomb Reynolds with Richard Castle kinda stinks. I like Fillion more when he's a tough guy, but I like that he's getting work, and once and a while does something cool and doesn't seem to be scared of very much.
BBBBBBUT.
There was a piece on NPR a few months ago. It was basically saying that many older but now defunct franchises might be getting a boost soon. Apparently studios make more money from DVD sales than they ever could from movie theater sales. The thinking is that well made novel structured TV series and made for TV movies (like BSG, the Wire) do far better on DVD than most movies do in theaters and DVD combined. Also, series/stories involving shows with cult-like followings, and well developed characters means less money and less risk on the studio's side.
Firefly was one of those mentioned that would be logical to take another look at, since the only cast members dead was Wash and the precher, and since there was still a heck of a lot of story left open.