It was a nice run for Christopher Nolan's "The Dark Knight," but it's time to vacate the no. 3 slot on the all-time U.S. box office grosses chart. As expected, "The Avengers" surpassed "Dark Knight's" $533.3 million take by grossing another $5.6 million on Friday for  $538.1 million to date.

Joss Whedon's remarkable take was achieved in only 28 days.  Comparatively, the all-time champ "Avatar" hit that cume in 36 days.  It's hard to believe that "The Avengers" can continue at a pace to overtake James Cameron's 3D game changer and its $749 million cume, but what about the no. 2 film?

"Titanic" held the top slot for 12 years, but was cast aside by "Avatar" just three years ago.  Its $600 million take was once seen as insurmountable, but that was before Hollywood realized the magic of higher 3D ticket prices.

Now, "The Avengers" is less than $62 million from crossing that threshold - or is it?  Paramount Pictures re-released "Titanic" in 3D this spring where it grossed another $57.8 million.  In theory, that means the lifetime gross for "Titanic" is now $658.6 million, but does the combined total count?  Studio pride is at stake, but unless "The Avengers" crosses the higher number, $600 million plus may not be enough to claim the no. 2 all time take.

Where "The Avengers" winds up is finally becoming hard to peg.  The Marvel Studios blockbuster is finally going to face increased competition for repeat business from "Snow White and the Huntsman" this weekend and "Prometheus" next Friday.  Moreover, it's going to start to lose many of its 3D screens to the aforementioned "Prometheus" (as well as IMAX screens), "Madagascar 3: Europe's Most Wanted" (also opening on June 8) and studio stablemate "Brave" on June 22. 

Can it weather the storm to earn $120 million or so?  Considering the disastrous run Walt Disney Studios had to deal with before "The Avengers" became a sensation, don't be surprised if they keep it in theaters as long as possible to eke out the take.  In any event, something to keep your eye on during the sweaty box office grosses in July and early August.