LOS ANGELES: "Mission: Impossible - Ghost Protocol" cruised to No. 1 at box offices on Sunday, even as major new movies opened on Christmas Day which may change top 10 results when final numbers are tallied.The new Tom Cruise movie rang up an estimated $26.5 million in U.S. and Canadian ticket sales over the three-day weekend, according to studio estimates, after expanding from a limited release in Imax and other large-screen theaters last week.Paramount Pictures, which released the movie, said it expects a four-day tally of slightly more than $40 million by Monday, when final estimates are reported. The film's cumulative ticket sales are expected to reach just over $72 after Monday.Indeed, the weekend box office race truly will finish on Monday because Christmas day annually is among the most crowded days in theaters and on Sunday, director Steven Spielberg's widely-anticipated "War Horse" makes its debut along with another newcomer, thriller "The Darkest Hour."Hollywood's major studios loaded the release schedule last week heading into the holiday, expecting the films to play well between now and New Year's Eve while parents and kids are away from work and school. As a result, a clear picture of how the movie studios fared…