When “Avengers: Age of Ultron” opens in May, it will likely have either the top-grossing or second-highest grossing debut in movie history.

Three years after they first stormed theaters, Earth’s Mightiest Heroes are still looking pretty muscular with most industry observers predicting a debut north of $200 million.

That means the movie will likely bypass “Iron Man 3’s” $175 million debut to become at least the second biggest of all time, though it’s the first “Avengers'” record-setting $207.4 million kick-off that is the barrier that Disney and Marvel would like to cross.

“It’s a movie that people are going to definitely go see,” said Phil Contrino, vice president and chief analyst at BoxOffice.com. “There’s almost nothing major opening between ‘Furious 7’ and when the film comes out, so there’s a lot of pent-up demand and a ton of goodwill from the first movie.”

The picture formally went on tracking Thursday, with services predicting a debut of between $190 million to $200 million, roughly $70 million more than the first film was predicted to make when it first went on tracking. Other analysts, such as BoxOffice.com, are projecting the film will make more than $210 million in its inaugural weekend.

It’s easy to see why box office cognoscenti are feeling bullish. Online expectations for “Avengers: Age of Ultron” are gargantuan, with fans on Twitter and Facebook enthusing over a second chance to watch Iron Man, Hulk, Thor and others assemble.

“It’s a beast in social,” said Ben Carlson, president and co-creator of the social media tracking firm, Fizziology. “When we look at the conversations people are having, it’s everything from people saying they’ve bought tickets to making plans with friends.”

Eleven percent of the social media chatter indicates that people intend to see the film, which Fizziology notes is high given that the volume for a typical blockbuster film is between 5% to 10% at a similar point in the build up to its release. It also outpaces the amount of conversation that surrounded the first “Avengers” by 400% and last summer’s “Guardians of the Galaxy” by 165%.

Those are heady numbers given that Disney and Marvel only started to advertise heavily this weeks. Initial teasers for the film were lapped up and heavily shared, breaking records on YouTube and Facebook. It helps that the studios didn’t deviate from a winning formula, bringing back stars Robert Downey Jr., Chris Hemsworth and Chris Evans and persuading Joss Whedon to take another spin in the director’s chair.

Even without a lot of television spots or posters, pre-sales for the film have been robust. A spokesman for Fandango declined to give specific numbers, but said the film is outselling the first “Avengers” by a significant percentage, and MovieTickets.com reports that U.S. advance ticket sales for “Avengers: Age of Ultron” are six times greater than they were for the first film at the same point. Already there are hundreds of sold-out showtimes across the country, Fandango said.

The problem with tracking is that for a film franchise that’s as widely known and enjoyed as “Avengers” it can be hard to pin-point what percentage of the population will turn out on opening weekend. Projections for recent hits such as “Furious 7” and “Fifty Shades of Grey,” for instance, missed the mark by tens of millions of dollars.

So the question is not whether “Avengers: Age of Ultron” will be huge. It’s can it grow to Hulk-like proportions.

“The buzz is through the roof and the trailers look fantastic,” said Eric Handler, an analyst with MKM Partners. “It should do just as much if not more than the first ‘Avengers.’ I see no reason why it couldn’t be the largest opening ever.”