You can bet that anyone who has shelled out for the box set will be in line to see the movie when it opens, and the last number I heard for box set sales was quite a while ago, and it was already over 500,000. And it still hovers near the top 10 on Amazon.
If there’s a million fans that are a guaranteed ‘base’, plus all the people they drag along with them, plus the people who like the show who never bought the DVDs, plus the science fiction fans who can be counted on to go see pretty much any SF movie, I think Serenity is guaranteed a pretty good opening weekend - perhaps not by the standard of a huge blockbuster movie with a $150 million budget, but for a movie with a $50 million budget. Then whether it’s a success or not will totally depend on A) the reviews, and B) repeat viewings.
I’m worried most about the reviews. When Firefly first came on the air, there were a lot of mediocre to bad reviews, including a few that called it a huge misfire and terribly bad. But after everyone had a chancce to see all the episodes, the reviews changed from mediocre to glowing, and now on Amazon there are 1600 user reviews, with an average of five stars.
I think the fan base should be lobbying people like Roger Ebert to please, please watch the box set before seeing the movie. A two thumbs up from Ebert and Roeper would go a long way towards helping this movie turn enough of a profit to greenlight the two sequels.