Numbers here- they're despicable!
Hollywood loves predictable blockbuster formulae. If they could, they'd dispense with creativity all-together and simply assmble the same elements every month for the same movie, over and over again. They'd reap the profits, draw up the budget for next year and sleep like babies.
This year the closest thing they've had to this situation is the digital animated 3D movie. You just can't go wrong with it. If Tommy Wiseau and Roman Polanski and Uwe Boll got together and made one, it would turn a profit in the first weekend. Which is not to take anything away for Despicable Me's #1 opening with $56 million, because I hear it's pretty good. But I'm just saying it would still make money even if it was bad.
Opening @ #3, Predators. Almost $25 million! Coulda been more if it had been in 3D I guess.
Twilight: Eclipse dropped 51% from opening weekend but don't worry about those guys... they've made over $250 mil to date.