Expectations are modest for the weekend’s three new wide releases — Sony’s “Stealth,” Disney’s “Sky High” and Warner Bros.’ “Must Love Dogs.” That means all the drama at the box office this weekend will rest on whether New Line’s “Wedding Crashers” can pull of the rare feat of claiming the B.O. crown in its third weekend of release. The best opening among the fresh titles is expected to fall in the midteens — also the territory in which the champ of the last two weeks, Warners’ “Charlie and the Chocolate Factory,” should finish. New Line hopes that if “Crashers” can hold on to the majority of business, as it did in its second weekend, falling just 25% to $25.7 million, it will finish around $19 million, which may be good enough to win the weekend. Through Wednesday, the Vince Vaughn-Owen Wilson R-rated laffer has grossed $92.1 million. After “Charlie” won last weekend with $28.3 million, another 50% drop would put Tim Burton’s movie around $14 million. So far, it’s brought in $127.8 million. Sony also thinks it has a shot to reach the top spot with “Stealth.” Tracking on the new movies has so far been soft. “Stealth,” the latest action movie from director Rob Cohen, has so far been attracting the strongest interest from males over 25. Sony will release the film in 3,495 theaters. The Diane Lane-John Cusack romantic comedy “Must Love Dogs,” starting with 2,505 locations, has been gaining traction mainly among women over 25. The Kurt Russell kid flick “Sky High,” which Disney is taking out on 2,905, is seeking success in a genre notoriously tough to track.