Inevitable, ‘how it’d take them this long?’ movie news from NBC New York’s Popcorn Biz:

Justin Theroux, who had a hand in writing both “Tropic Thunder” and “Iron Man 2,” is heading to Fashion Week in Paris to prepare to write the “Zoolander” sequel.

Ben Stiller, star, director and co-writer of the original, is working on a new script with Theroux, who plans to “immerse himself on what is current in fashion,” a source has told Deadline Hollywood.

“Zoolander” was released a couple of weeks after 9/11 and fared poorly at the box office as a result, taking in a lowly $45 million. But it’s subsequent DVD sales, near ubiquity on cable TV and the constant requests Stiller gets to do “Blue Steel,” Derek Zoolander’s signature look, are all testament to how popular the film truly is.

Assuming they can get Owen Wilson back on board, as well as cameos on a par with the original — Will Ferrell, Milla Jovovich, David Bowie, the sequel could easily take in three times the original.