Five Reasons Iron Man 2 Could Be Eclipsed at Summer Box Office

Eclipse, Toy Story 3 pose threats to Robert Downey Jr. superhero sequel

Iron Man 2 isn't going to be huge. It is huge.

More than a thousand screenings are sold out. Overseas business has been big. All this, and the movie doesn't even open here until midnight tonight.

But wait—is it too soon to hand over the summer crown? Can we come up with five good reasons why Robert Downey Jr. might get taken down by Robert Pattinson or Woody the cowboy? Oh, sure. Wanna see 'em?

1. It's Iron Man 2, all right—as in 2-D. You think Clash of the Titans is one of the year's biggest movies because it's one of the year's best movies? Right. Clash of the Titans got to where it is today because it's one of the year's most expensive movies. In 2010, 3-D ticket prices are the ticket, and Iron Man 2 doesn't haven't 'em. Toy Story 3 (opening June 18) and Shrek Forever After (May 21) do. (And, yes, Iron Man 2 has IMAX, but so will its 3-D competition.)

2. Compared to the original Iron Man, the buzz on Iron Man 2 is somewhat less buzzy. Note, somewhat. We didn't say a lot. But there are little things. Like MovieTickets.com letting it drop that "plenty of tickets are still available." Or Flixster, the movie community site, remarking that interest, while high, was higher for Alice in Wonderland and—yeesh—Clash of the Titans. Or Metacritic weighing in with a good, but not great, score of 61 (as opposed to the first film's 79). Meanwhile, the buzz is building on films like Christopher Nolan and Leonardo DiCaprio's Inception (July 16).

3. Eclipse could cross over. With the director of 30 Days of Night scaring up the action in the third Twilight movie (opening June 30), the franchise may not just be for fanggirls anymore. "I think Eclipse could sneak up, and be a lot closer to Iron Man 2 than some people give it credit for," BoxOffice.com editor Phil Contrino told us.

4. Spoiler alerts don't just apply to Lost. "Right now, Iron Man 2 is the one to beat," Exhibitor Relations' Chad Hartigan told us. "[But] Eclipse, Inception and Toy Story 3 [are] the possible spoilers."

5. It'll...Or, it'll...Oh, never mind. We can't come up with anymore. As things stand now, Hartigan thinks Iron Man 2 has a good shot at Dark Knight's opening weekend record. BoxOffice.com is calling for a summer-topping, $410 million overall domestic gross. So, maybe we were wrong: Maybe Iron Man 2 is going to be huge.