It was a potent weekend at the box office as "Transformers: Dark of the Moon" stayed on top with another $47 million according to studio estimates.  The Michael Bay threequel has now grossed $261 million domestically and over $558 million worldwide in just 12 days.  It's also officially passed "The Hangover, Pt. II" as the biggest movie of 2011.

Among new releases, "Horrible Bosses" continued the recent string of impressive R-rated comedies with a $28.1 million debut in the second spot.  That is less than "Bad Teacher's" $31.6 million last month, but "Bridesmaids'" $26.2 million debut in May.  The comedy was no doubt helped by its hard to ignore concept (who hasn't wanted to knock off their employer?) and strong supporting cast including Jennifer Aniston, Jamie Foxx, Kevin Spacey and Colin Ferrell.

Kevin James' "Zookeeper" made $21 million, which was good enough for third, but significantly lower than Sony Pictures and MGM had hoped for when moving the picture to the summer.  The family friendly comedy was originally scheduled for an October, 2010 release.  It's unclear if less competition would have made it more palatable for adult audiences.

Dropping to the fourth slot was "Cars 2" with another $15.2 million and $148.8 million so far. The Pixar sequel should pass the $200 million mark easily, but matching the original's $244 million domestic cume is likely out of reach.

Still making noise in the fifth slot was "Bad Teacher."  The Cameron Diaz comedy grossed $9 million for a $78.7 million overall take.  The picture is one of Diaz's best solo efforts of her career and should eventually hit the $100 million mark.

Friday's new releases include the long awaited "Harry Potter and the Deathly Hallows, Pt. 2" and "Winnie the Pooh."

Final box office results are released on Monday.