A number of factors - including diminishing returns and real-world tensions - could lead to Episode II losing its top spot this weekend after only two weeks' release. From the Hollywood Reporter via Yahoo:

To be sure, "Sum" does face a couple of unknowns. With Ford having retired from the role, young whippersnapper Ben Affleck has stepped into Ryan's shoes. While the plot line remains contemporary, Ryan's character has been spun back in time so that Affleck can play him as a rookie just beginning his CIA career. Forced to recast the role, Paramount may well have made a virtue out of necessity, because Affleck's younger fan base probably will expand the demographic appeal of a series that has generally appealed to older males. Just to play it safe, the studio has surrounded the young star with such old reliables as Morgan Freeman.

The bigger question is whether some moviegoers might be scared off by a story line that could appear to be disquietingly real. With the threat of nuclear war hanging over India and Pakistan even as the U.S. government warns of possible future terrorist attacks at home, "Sum" risks being overtaken by the headlines. But that, too, could also play to its advantage, raising the movie's profile as it becomes part of the ongoing national debate over the war against terrorism.

In any event, "Star Wars: Episode II -- Attack of the Clones," last weekend's boxoffice leader with a four-day holiday gross of $60 million, is heading into its third weekend. While strong, "Clones" isn't demonstrating the same staying power as it 1999 predecessor, "Star Wars: Episode I -- The Phantom Menace." And that could open the door for "Sum" to blast its way into the top spot.