Hollywood appears to be treading water for another week prior to the official opening of the blockbuster summer season with the opening of Iron Man 3 next weekend. Opening wide this weekend is Paramount's Michael Bay comedy thriller Pain and Gain, which most forecasters agree is unlikely to pass the $20-million mark at the box office. The film is likely to sell tickets based on the popularity of its two stars, Dwayne The Rock Johnson and Mark Wahlberg. And, given the fact that it reportedly cost a modest $26 million to produce, is unlikely to lose money. Also opening wide is the Lionsgate R-rated comedy The Big Wedding, starring Robert De Niro, Katherine Heigle, Diane Keaton Amanda Sefried, Topher Grace, Ben Barnes, Susan Sarandon and Robin Williams. The critically flogged flick is projected to earn around $10-15 million and probably finish in third place behind the second week of Universal's Oblivion (which could challenge Pain and Gain for the weekend's top spot).