Continuing the steady summer franchise stream, 20th Century Fox’s “X-Men: First Class” is ready to school the worldwide B.O., unspooling today at 3,641 domestic locations and in 55 overseas territories.Fox has the global playing field to itself this weekend with no other wide releases entering the market. But bizzers will keep a watchful eye on apair of holdovers, Warner Bros.’ “The Hangover Part II” and Paramount-DreamWorks Animation’s “Kung Fu Panda 2,” after both opened to boffo holiday runs last weekend. Still, it’s unlikely either film will be able to match the fresh mutant power of “X-Men.” Fox’s fifth “X-Men” outing, prequel “First Class” is expected by some to bow at $60 million-$70 million based on pre-weekend tracking. Fox, however, has more modest expectations in the high-$40 million range. While “First Class” opens unchallenged among wide releases, new and expanding limited releases continue to crowd the specialty scene. A pair of Toronto pickups, Focus Features’ “Beginners” and the Weinstein Co.’s “Submarine,” bow domestically today. “Beginners,” starring Ewan McGregor and Christopher Plummer, opens at five locations, while Brit helmer Richard Ayoade’s coming-of-age tale “Submarine” goes out at two theaters each in New York and L.A. Meanwhile, Fox Searchlight looks to broaden its success with “The Tree of Life” after last weekend’s 2011 second-best per-screen average of $93,230. “Tree” expands to 20 locations, up from four; cume is $589,840. Sony Pictures Classics’ “Midnight in Paris” — the year’s per-screen champ — has cumed $3.5 million after two weeks, and the Woody Allen film expands to 147 locations this weekend. Fox’s newest “X-Men” pic, starring James McAvoy and Michael Fassbender, has plenty of heat behind it going into the weekend. But the film is a prequel and doesn’t sport the franchise’s original cast, so some bizzers are questioning how high “First Class” can fly. Still, the movie cost significantly less than its predecessors. Pic, budgeted at a reported $135 million after rebates, is generating strong word of mouth aided by glowing critical response. Positive reviews could attract moviegoers who are on the fence about whether to see this newest “X-Men” rendition. The film should easily entice the franchise’s most hardcore fans, but the studio hopes to broaden beyond just fanboys. “If they’re breathing, we’re going after them,” Fox distrib boss Bruce Snyder said candidly. Fox’s original “X-Men” bowed to $54 million in 2000, while Warner Bros.’ reinvention of the Batman franchise, “Batman Begins,” opened at $48.7 million. That pic, however, bowed on a Wednesday and tallied $72.9 million in its first five days. The most recent “X-Men” offering, “Wolverine,” opened May 1, 2009, with $85 million. “First Class” will have to vie for under-25 auds with “Hangover II.” How tough the competition is will depend on the laffer’s drop, which given unfavorable reviews could be as much as 50%, according to some B.O. observers. “Hangover II” has cumed almost $150 million domestically, with its worldwide tally well above $200 million. Par’s “Panda 2,” with a global cume approaching $150 million, essentially has the family market to itself — and that should continue until “Cars 2″ bows on June 24. Both “Hangover II” and “Panda 2″ did exceptionally well last weekend overseas, especially considering Disney’s “Pirates of the Caribbean: On Stranger Tides” collected $137 million in its second frame. “Hangover II” expands this weekend to Germany and Russia, while “Panda 2″ will broaden to mostly smaller European markets. Major international markets for “First Class” include Australia, Brazil, France, Russia and the U.K.