'The Avengers' may already be the third highest-grossing film of all time, but it looks like this summer's sequel 'Avengers: Age of Ultron' could surpass it, at least when it comes to opening weekend box office receipts. Industry researched boxoffice.com predicts that ‘Age of Ultron’ will rake in $217m domestically (in US and Canada) over its opening weekend when it’s released on May 1st, smashing the record of $207m currently held by 2012’s ‘The Avengers’.