Although it's not set to be shown on the big screen until 2015, Marvel's next installment of the highly anticipated superhero team-up of the Avengers has been getting a lot of attention from both the media and the fans.

Numerous photos of onsite filming have been spreading online like wildfire, especially now that almost everyone's phone has a camera. Students at the University of East Anglia in Norwich spotted Joss Whedon with his cast of superstars, their stunt doubles and the filming crew shooting scenes in and around their campus.

Marvel plans to outperform the first installment of "The Avengers" -- the third-highest-grossing film of all time, according to reports. However, even if photos of the actors in their superhero costumes are constantly being uploaded from their filming locations, they still can't be considered spoilers, since not much has been written or shown so far regarding the new movie's plot. The only teaser so far is the brief clip in the credits of "Captain America: The Winter Soldier" of siblings Quicksilver and Scarlet Witch -- being played by Aaron Taylor-Johnson and Elizabeth Olson, respectively.

According to JoBlo.com, three versions of Ultron will be featured in the upcoming Marvel film -- including his original state and a continuously upgrading version. The villain, who must be stopped by the assembly of superheroes, will be played by James Spader, who appeared in the sci-fi blockbuster film "Stargate" as Egyptologist Daniel Jackson.

Another rumor is that Tony Stark will again commission his army of iron men to assist the Avengers in saving the world. Stark Tower will become their new headquarters and the center of worldwide security. However, none of the rumors have been confirmed, and fans will know the final details only upon the release of "Avengers 2: Age of Ultron" in 2015.