Box office roundup: 1) Revenue continues to pour in at a breakneck pace for Disney's (DIS) Iron Man 3. Early estimates for the movie's opening U.S. weekend are for a $170M haul (vs. ~$150M consensus) to push global sales for the film to over $360M. 2) Keep an eye on IMAX (IMAX). The company is seeing the percentage of moviegoers in the U.S. choosing to see big tentpole films in the big-screen format increase - including an impressive 10% this weekend for Iron Man 3. 3) Analysts at Cowen and Co. think Warner Bros. (TWX) could have a big summer with The Hangover Part III and The Great Gatsby set up to beat estimates while they warn DreamWorks Animation (DWA) could struggle with 3D computer-animated film Turbo facing serious competition.