It's hard to imagine a $133.6 million opening being a disappointment, but after all the hype, polling and the largest screen count ever, there has to be some surprise at Marvel Studios, Marvel's new owner Walt Disney Studios and distributor Paramount Pictures that "Iron Man 2" didn't come close to breaking the all-time weekend mark of $158.4 million.

"Iron Man 2's" debut, however, still places it No. 5 all time behind reigning champ "The Dark Knight," "Spider-Man 3," "The Twilight Saga: New Moon" and "Pirates of the Caribbean: Dead Man's Chest."  "Shrek the Third's" $121.6 million tally in 2007 now falls to sixth.  For more comparison, "Alice in Wonderland" had a massive $116 million opening this past March, but benefited from more expensive 3-D ticket prices.  Last year's first summer blockbuster, "X-Men Origins: Wolverine," found only $85 million when it debuted and the original "Iron Man" grossed a then surprising $98.6 million in 2008.

It's worth noting that the only film to open over $108 million and not finish with over $300 million domestic was "New Moon's  $296.6 million last year. This "Iron Man" sequel, on the other hand, should have no problem passing its predecessor's $318 million.  Especially with an "A" Cinemascore from audiences and little competition expected from either "Robin Hood" or "Prince of Persia: The Sands of Time" the rest of this month.

In second place was last week's No. 1, "A Nightmare on Elm Street."  The reboot had a horrific fall taking in just $9.1 million for a new total of $48.5 million.  Can a sequel really be in the works?  We have our doubts.

Third place went to "How To Train Your Dragon" which lost almost all its IMAX screens, but still pulled in $6.7 million to cross the $200 million mark. A sequel is definitely in the works for that critically acclaimed franchise.

"Date Night" held steady in fourth with $5.3 million and a new cume of $80 million.

Surviving somewhat in fifth place was CBS Films' "The Back-Up Plan."  The J-Lo romantic comedy found $4.3 million in its third weekend for a forgettable $29.4 million so far.

Next weekend's new releases include the aforementioned "Robin Hood," "Letters to Juliet" and "Just Wright."

What did you think of "Iron Man 2"?  Will you see it again?  Share your thoughts below.