SAN DIEGO — Rumor had it that during their highly anticipated Comic-Con panel Marvel Studios would announce which actor is playing the new Doctor Strange in Scott Derrickson's upcoming big screen adaptation. Rumor also had it that Marvel would reveal who is playing Captain Marvel, a much-needed super-powered female Avenger that is expected to cameo in "Avengers: Age of Ultron." Neither event happened. Instead, the studio announced that a sequel to "Guardians of the Galaxy" has already been greenlit and it already has a release date of July 28, 2017. Oh yeah, and they showed a massive amount of footage from Joss Whedon's "Avengers" sequel with almost the entire cast on hand.

A who's who of Hollywood stars including Robert Downey Jr. (Iron Man) Chris Hemsworth (Thor), Chris Evans (Captain America), Mark Ruffalo (Hulk), Samuel L. Jackson (Nick Fury), Aaron Taylor-Johnson (Quicksilver), Elisabeth Olsen (Scarlet Witch), Jeremy Renner (Hawkeye), Paul Bettany (Vision) and Cobie Smulders (Maria Hill) made their way to Hall H. Also on hand was James Spader, who plays the villainous Ultron, and, eventually, Josh Brolin, who was announced as the voice of Thanos. Of course, many in the media already knew this because Brolin is heard voicing the character in "Guardians." That being said, it was an impressive crew of actors who only had time to answer one question each from the moderator.

Robert Downey Jr.
Downey was the first to appear on stage dancing to Michael Jackson's "Don't Stop 'Til You Get Enough" and throwing roses into the audience. He also gave a white rose to both Olsen and Smulders.

"It keeps getting better," Downey said. "This is the longest bench of talent I've ever been apart of and we have a really good movie coming out for you next year." He also added, perhaps looking for some sympathy, "I've become a little less significant every time, which is fine because they are just so damn good."

Jeremy Renner
As usual, the "Hurt Locker" star is often at a loss for words in public appearances or talking to the press. Renner called the role "a wonderful blessing. It's easy to want to join [this team.] Wasn't very hard for me to do it. Glad to be part of this amazing group of humans sitting at this table."

Mark Ruffalo
Experiencing a career year with "Normal Heart" and "Foxcatcher," Ruffalo joked, "They don't treat me like this at home. It's pretty..."

He was then interrupted by the crowd chanting, "Hulk! Hulk! Hulk!"

"That's really nice," Ruffalo said, beaming. "People don't know who I am other than Hulk. I'll walk down the street and they'll yell, 'Hulk! Yo, Hulk!"

Chris Hemsworth
After appearing on the same stage earlier in the day to promote Michael Mann's new thriller "Blackhat," Hemsworth returned to get some ribbing from his co-stars for his huge biceps. He noted that "Age of Ultron" is "one of the best experiences [he's] had on a set, off a set. To be a part of this madness is just awesome."

As a follow-up, Hemsworth was asked if there was anything he'd like to do as Thor on the big screen that he hasn't had the opportunity to do yet.

"Turn him into a woman," Hemsworth deadpanned. "I don't want to speak too early and jinx it, but I think it will be my Oscar."

In the comic book, it was recently announced that Thor's mantle of the God of Thunder is being taken over by a woman. The informed audience was well aware and roared in approval.

Cobie Smulders
It was unclear if Smulders would return for "Age of Ultron," but she said she "hoped" she'd get the call. "Joss was the one who brought me into this world, and it's just been fun," she said.
"I just keep going on the films and on the TV show. I'm just so grateful."

Samuel L. Jackson
Always the most candid member of a very candid cast, Jackson reflected on his many visits to Comic-Con over the years. "I've been coming here since 'Star Wars: Episode I' and every year I come here and it validates that I belong," he admitted. "And I get all this energy and love from everyone, which makes me feel like making movies the rest of the year. I make movies because I want to see myself in them. It just energizes me."

Chris Evans
Evans, who is celebrating the box office and critical approval of "Captain America: The Winter Soldier" alongside the cinephile endorsement of "Snowpiercer," reflected on where Steve Rogers is in "Age of Ultron." Is he still the fish out of water we've seen in his last three appearances?

"I think he's getting there," Evans said. "He's not just amazed at cellphones and the internet, but I think he's still looking for a place to belong. He's been a servant, a soldier. He has had this chain of command. Since S.H.I.E.L.D. fell apart I think he's searching for home."

Aaron Taylor-Johson
Like Evans, Taylor-Johnson has a previous history as a superhero ("Kick-Ass"). He said he was a big fan of what Whedon did with the first "Avengers" movie.

"I think what Joss did with the first one was a mission: impossible to do," he said. "Everyone had their moment. What's great is you get these characters in the same room and they have banter and bounce off each other. I thoroughly enjoy all the Marvel movies and am so excited to be part of this one."

Paul Bettany
If any actor could use the kick-start of being in a Marvel movie it's Bettany. He's slogged through one bad genre movie after another over the past few years and barely anyone realized he was the voice of Jarvis in all the "Iron Man" movies (as well as "The Avengers"). Times have changed.

"Now they are going to make me work for my money," Bettany said of his role as The Vision. "I used to turn up to a dark room for 45 minutes and get a bag of cash. Everyone has been incredibly welcoming. It's the most exciting thing that happened to my children."  

He added that not only did he have to keep the live action role a secret for a year, but so did his kids and that really impressed him.

James Spader
It's rare that an actor appears (and emphasis on "appears") to have such a negative reaction to Comic-Con as James Spader has. The "Blacklist" star plays the villain in question, but coming to the annual San Diego comic, movie and TV fan mecca hasn't sat well with him. Can you get at his discomfort in the following remarks?

"I have always thought my whole life that life could never get weird or crazy enough for me," he said. "This place may be the weirdest, craziest place ever. I thank you for that."

As for his role, Spader remarked, "I play an 8-foot robot. Shooting this film was as startling and challenging and surprising as coming here for the first mite. Doing this film was so entirely new, the process of making it, playing this character, all of the people, the world I was entering, even the world these movies inhabit. Also just the part of the movie business these movies inhabit is just unimaginably exciting."

Elizabeth Olsen
Olsen, on her first panel, broke the first rule of Marvel. You do not use the word "mutant," especially when you are playing a character who is a mutant in the comic books, the Scarlet Witch. Because of contractual issues with Fox's "X-Men" series, that term cannot be used on the big screen in a Marvel Studios movie.

It began innocently enough. Olsen noted, "I was first really intimidated by everyone I was working with. It's fun to bring a new element to the game. There is now magic, mutated people…"

That prompted a number of shoot-outs from the audience (although whether they were mad at her for saying it or afraid she was going to get in trouble was unclear). After getting a reminder that that word is off-limits, Olsen segued to discussing her character's power set.

"I practice daily just staring at a pencil trying to get it to move," she joked. "For hours. It's been flying, I'm nailing it."

Realizing Olsen might need some help, Downey cracked, "She actually cast a spell on me two weeks ago and hopefully before this is done she'll relieve me of it."

He waited a beat: "It burns."

Downey was reminded that you could read a lot into that comment and he beamed.

After a quick video introduction from a very pregnant and close-to-delivery Scarlett Johansson — taken by cellphone, no less — the Hall H audience enjoyed an extended preview of "Age of Ultron." Check out a write-up on that from HitFix's own Drew McWeeny here.

Before the night was over, however, Downey took the mic and introduced none other than Josh Brolin. He walked on to the stage wearing the Infinity Gauntlet (a massive glove which has room for the Infinity gems on it) and demanded a rose from Downey. He took it and chopped the petals off with his mouth. After a few moments of waving and cheers, Earth's Mightiest Heroes exited the stage having conquered Saturday's Comic-Con schedule.

"The Avengers: Age of Ultron" opens nationwide on May 1, 2015