Time was, months or even years might pass before a studio decided it was interested in a sequel to a popular film. But these days, the culture of franchises in Hollywood is such that studios are taking flyers on follow-ups months before the first film gets released. Pretty soon they'll be committing to a sequel before they even decide to make the original.

The news Wednesday that Disney has already commissioned the writers of the December movie "Tron Legacy" to write a second (and possibly third) film in the rebooted franchise is only the latest example. Last year Warner Bros. created a stir when it seemed to move forward with a "Hangover" sequel two months before the film was released.

Then came Sherlock Holmes, which signed new writers to tackle a second Conan Doyle-derived tale as many as three months before the holiday film hit theaters. And a few weeks ago we reported on producers and executives bringing back the writers of "Diary of a Wimpy Kid" for another go-round before the first movie came out.

In some ways, there's a logic to what studios are trying to do. Companies shell out millions on development anyway; if executives think they have a hit on their hands, they may as well put a marker on an existing property. There's also a timing issue: Hits are scarce and investors want results quickly, so better to maximize every bit of available time.

A quick turnaround on a sequel is also, not coincidentally, a savvy political move. If you're a studio executive worried about whether a film will be a hit, pushing forward a sequel is as good a way as any to telegraph confidence to your colleagues and bosses (and also, presuming the studio wants the news out there, to audiences).

But in watching sequel-mania hit earlier and earlier, it's tempting to ask these cowboys to slow down. Part of the defense for premature sequelization is inevitably that a studio isn't really committing to anything; they can, after all, always change the script or chuck it and start over if they don't like it.

But developing a sequel months before a movie comes out sends a questionable, if not hubristic, message to audiences -- "We're thinking about cramming another movie down your throat, and before you've even told us if you've liked the first one."

It also risks suffocating a process that, while always at least part calculation, in some circumstances can be organic.  The best sequels grow out of not just the original film but the reception to it. Plenty of movies whose sequels outdid the original -- everything from "The Godfather" to "Spider-Man" -- happened that way because writers got a chance to consider both the mythology and the reception to it. Start writing a new film before you fully know what you have with the first one and you risk missing what makes the original worthwhile (and worthy of a sequel in the first place).

We get that there's a desire to go quickly. But there are also reasons to wait, and not really much downside to doing so. Take your time, Hollywood. We're not going anywhere.

--Steven Zeitchik

Photo: "Jaws" sequel DVD cover. Credit: Universal Pictures Home Video

In the newly released trailer for December's "Tron: Legacy," the long-awaited sequel to the 1982 cult classic, it's at first a bit jarring to see Jeff Bridges in such a fast-paced, futuristic setting. Bridges has, after all, spent the past few months on the awards circuit inhabiting the laid-back cowboy attitude of "Crazy Heart's" Bad Blake.

But once you get past that, you get the sense that the movie is a fanboy's dream, with a world that will look pretty fantastic in 3-D, what with hi-tech Recognizer vehicles, neon game-warrior suits and, of course, the beloved Bridges. 

In the trailer, we're immediately introduced to newcomer Garrett Hedlund, a.k.a. Sam Flynn, the son of computer programmer Kevin Flynn, the protagonist from the first film and a role that Bridges reprises here. Sam is told by old "Tron" pro Alan Bradley that some new information about his father, who disappeared 25 years ago into the digital world of Tron, has surfaced. He hops on his Ducati and heads over to Flynn's arcade, whose many games are now covered in dusty cobwebs and plastic tarps.

What he uncovers there catapults him into Tron, a dark, ominous world with menacing skies and neon lights where he will be reunited with his father and try to save him from the Tron program. (For a deeper analysis, check out this awesome play-by-play on our sister blog Hero Complex.)

Over the weekend at the Indie Spirit Awards, Olivia Wilde -- who plays Sam's friend Quorra in the film -- told us that though the sequel seems like a big-budget adventure flick, many fans don't realize that the original film was seen as risky.