If you just can't get enough of Joss Whedon (not sure if that is possible, given the speed at which the man works) and don't want to wait a few more days to see some Serenity special features, then Sci Fi Wire has got you covered. They have managed to obtain an exclusive look at an extended scene from the special features side of said DVD, featuring a longer look at Shepherd Book. Other features on the DVD will include Future History: The Story of Earth That Was, What's in a Firefly and Re-Lighting the Firefly, and an introduction by Whedon.
As much as the movie wasn't a box office smash, I still found it enjoyable, and I look forward to the DVD. Whedon is an interesting guy, and he's always worth listening to when he gets to explaining his projects. His passion is so infectious that you find yourself enjoying what he's working on even if you've never actually seen it.