It wasn’t long ago when the biggest summer blockbusters pivoted around the July 4 holiday — and why not? It’s the all-American weekend. Then Hollywood moved up the fest ivities to Memorial Day, the better to cash in on the summer DVD season. These days, the biggest “summer” weekend at the box office occurs in early May, when the snow and ice is thawing in some parts of the country.

This year, “Iron Man” sprinted out of the gates on May 2, asserting itself as the blockbuster to beat with a $100 million opening weekend. Then last weekend, the latest “Indiana Jones” chapter raised the stakes further, pulling in $151 million over the five-day holiday weekend. And this weekend, “Sex and the City” will surely be another sizable hit (though speculation is raging as to just how big it can be, given the niche audience of the television show).

The three biggest summer movies of the year, all more or less done at the box office before summer even arrives. So the question becomes: Now what?

Talking to moviegoers around town, there is, of course, a great deal of interest regarding the new Batman installment, “The Dark Knight,” which opens July 18. But after that, the pickings become remarkably slim. Some curiosity surrounds Pixar’s summer offering, “Wall-E” (June 27), and the Will Smith superhero comedy “Hancock” (July 4) is getting some buzz. But with three weeks to go before summer arrives, and then 12 weeks of the season itself, it is the distinct lack of excitement surrounding everything else that is more interesting.

In the past year, there has been much discussion within the industry about the eroding Hollywood brands and the diminished mainstream appeal of movie stars. Last autumn, as such star-studded affairs as “Charlie Wilson’s War,” “Lions for Lambs,” “Rendition,” and “Michael Clayton” opened to sleepy box office receipts, it became clear that marquee names such as Tom Hanks, Julia Roberts, Tom Cruise, Robert Redford, and George Clooney do not guarantee a hit. Indeed, looking back at the 15 most profitable films of 2007, one finds titles like “Transformers,” “Alvin and the Chipmunks,” “300,” and “Knocked Up,” all of which lack A-list celebrities.

So this summer, we’re preparing for yet another reconsideration of which A-listers still matter to an audience that is increasingly interested in familiar stories and franchises rather than in star caliber. The trio of “Wall-E,” “Hancock,” and “The Dark Knight” reflect some of the summer’s safest brands.

In “Wall-E,” a cute little robot who roams Earth long after its human inhabitants have disappeared will represent Pixar Studio’s attempt to do for robots what “Cars” did for joking automobiles and “Ratatouille” did for cooking rats. “Hancock” is yet another bankable Will Smith enterprise. Of all the movie stars working today, Mr. Smith remains perhaps the most reliable — “I Am Legend” was the sixth-biggest film of 2007, “The Pursuit of Happyness” was the 10th-biggest of 2006, and “Hancock,” about an alcoholic ex-superhero trying to resuscitate his public image by hiring a marketing expert, is sure to fare well at the window.

“The Dark Knight,” meanwhile, has three things going for it: the reinvention of the “Batman” brand in 2005 with “Batman Begins,” which rekindled interest in the hero; the return of Christian Bale as the man behind the mask, and the final performance, as the Joker, of Heath Ledger, who died tragically in January.

If these three properties — the Pixar title, the Will Smith comedy, and the “Batman” sequel — represent the safe bets, then what is stunning about the summer’s remaining titles is how underwhelming they may prove to be. Throughout June, we’ll see a number of formerly bankable “Saturday Night Live” stars trying to re-assert themselves as icons of the silver screen.

Next Friday, Sandler will try to bring some ethnic laughs to the theater in “You Don’t Mess With the Zohan,” playing a former Mossad agent who fakes his own death so he can fulfill his dream of being a hairdresser in New York. Mr. Sandler’s last comedy, “I Now Pronounce You Chuck and Larry,” was a hit, but it was his first in a few years, and many are wondering if “Zohan” won’t fall more into “Click” territory.

Two weeks later, Mike Myers will to attempt to stage his own triumphant comeback as a spiritual self-help master in “The Love Guru” (June 20). Moving into July, Will Ferrell will go up for a rebound of his own after the weak business of “Semi-Pro,” which made only $33 million. In “Step Brothers” (July 25), Mr. Ferrell and John C. Reilly play two new stepbrothers who compete for the love of their recently married parents.

But it’s not just actors trying to find their strides again. Director M. Night Shyamalan, who has frustrated audiences and critics alike in recent years with “The Village” and “Lady in the Water,” is back with another huge, made-in-secret mystery, “The Happening.” Universal Pictures, meanwhile, is essentially taking a mulligan on Ang Lee’s failure of 2003, “The Hulk,” with this summer’s “The Incredible Hulk,” starring Edward Norton in place of Eric Bana. And then there are returning franchises like “The Mummy” (August 1), “The X-Files” (July 25), and “Star Wars” (the animated “Clone Wars” opens August 15), which at one time were far more prominent franchises than they are today.

With nothing as bankable as “Indiana Jones,” “Spider-Man,” or “Pirates of the Caribbean” on the horizon, this summer’s story line becomes less about the hits than about the potential disappointments. Is there anyone out there who still wants to watch Mr. Myers play another variation on his famous characters? Are there enough “X-Files” fans out there to make a new movie worth the cost of production? Does anyone care about “The Incredible Hulk” (including its star)? What if Mr. Shyamalan’s demise continues unabated, with “The Happening,” his first R-rated outing?

Meanwhile, waiting in the wings is a new generation of emerging names and brands, all eager to fill the void. In June, Steve Carell may just sell more tickets with “Get Smart” (June 20) than Mr. Norton does the previous weekend with “The Incredible Hulk.” In July, it might be reality TV that wins out, as the huge Sundance documentary “American Teen” (July 25) hits theaters, targeting the teenybopper MTV crowd.

Then in August, just waiting to pounce after the dog days of summer, are three projects that may surprise the establishment. In “The Rocker” (August 1) Rainn Wilson — another “Office” worker — gets his first starring role as a middle-age, one-time rock star who gets a second chance to front a band. The Judd Apatow crew is back in action with “Pineapple Express” (August 8), starring Seth Rogen as a stoner who accidentally witnesses a crime committed by a corrupt cop. And “Hamlet 2” (August 22), the biggest hit from this year’s Sundance Film Festival, stars Steve Coogan as a failing high school drama teacher who writes a sequel to Shakespeare’s masterpiece in the hope of saving his school’s drama program. It is creative, bizarre, and inspired — probably everything that “You Don’t Mess With the Zohan” and “The Love Guru” are not.

ssnyder@nysun.com