Just to play devil's advocate, it's probably worth pointing out that the whole notion that series need to be serialized and that iconic characters need to experience character growth and complicated story arcs is a relatively new one. Sherlock Holmes, Doc Savage, Fu Manchu, James Bond, Tarzan, Zorro, Dracula, and so on never really changed all that much, and, with minor exceptions, you could pretty much read (or watch) their adventures in any order.
(Says the guy who was watching THE BIG SLEEP, an old Phillip Marlowe detective story, again last night.)
Don't get me wrong. I love a good, serialized TV drama or comic book saga as much as the next person. (Can't wait to see how DEXTER wraps up!) But I like to think that there's still room for an old-fashioned standalone adventure that, as The Wormhole said, doesn't require readers to be completely up-to-date on some complicated continuity to enjoy on its own terms.