With the world premiere of Captain America: The Winter Soldier occurring last week and Guardians of the Galaxy deep into post-production, writer and director Joss Whedon is beginning to shoot the closing chapter on Phase 2 of the Marvel Cinematic Universe with The Avengers: Age of Ultron. The team-up sequel already began shooting second unit in South Africa a few weeks ago and this week we’ll get our first tease of the production during ABC’s Marvel Studios: Assembling a Universe special tomorrow.

While we don’t know what the limited footage of The Avengers 2 will include, we can only hope it at least showcases some of the new characters the sequel will introduce, from siblings Quicksilver and Scarlet Witch, to the more robotic Vision and Ultron. Marvel Studios president of production Kevin Feige only promises that fans will “certainly get more than just a peek at some of the new fun things we have in store.”

Speaking with Movies.com during the press junket for Captain America: The Winter Soldier, Feige talked about how much work is going into the new villain of the Marvel Cinematic Universe, a threat so dangerous he’s able to bring Earth’s Mightiest Heroes together again.

“Introducing the new characters is going to be a lot of fun for the movie. That ever-changing roster is very important in the Avengers comics, and so how do we start to play with that [on the big screen]? Also our bad guy is great. I think people are going to very, very excited to see what we’re doing with the voice that Joss [Whedon] is bringing to life with James Spader for Ultron. We love Ultron from the comics, and have always loved Ultron, and at no point do we want him to just be a robot. We want him to have an extreme personality and attitude, and James Spader is doing an unbelievable job. Again, for us it’s always about subverting expectations. Whenever you think you know what’s coming next, we surprise people or deliver it in a slightly unexpected way. And Spader is doing that with Mr. Ultron.”

We know from previous interviews with Feige that not only the voice of James Spader (The Blacklist) will be used for Ultron, but his face and body as well. From what we’ve heard about Paul Bettany’s makeup and costume tests, it sounds like a similar approach will be used for Vision as well, a character that’s yet to be officially confirmed.

Some fans may see a red flag when reading the line from Feige where he says “it’s always about subverting expectations” because while we can appreciate the savoring of the moviegoing experience, for films based on comics with such a large following, this could indicate that Ultron will be very different from how he’s presented in the books, and if it’s not a better way, there’s potentially another Iron Man 3-Mandarin controversy on the horizon.

We already know from Joss Whedon that the origins of Ultron will be different in the Marvel Cinematic Universe. In the comics, it’s Hank Pym who creates Ultron, but in the films we won’t meet Pym until after The Avengers: Age of Ultron when Michael Douglas plays him in Ant-Man.

Ultron needs to be more menacing and dangerous than The Avengers’ first foe, Loki, especially if he’s potentially going to kill a member of the team, or at least force an inevitable change in the team’s roster. At the same time, Ultron also needs to be able to command the screen, which Spader is a leader at – but not if he was limited to being robotic as Feige points out. So, on the whole, this sounds promising, despite the challenge in bringing the character to life.

More: Details on Vision’s Costume in ‘The Avengers 2′

Captain America: The Winter Soldier hits theaters April 4, 2014, Guardians of the Galaxy on August 1, 2014, The Avengers: Age of Ultron on May 1, 2015, Ant-Man on July 17, 2015, and unannounced films for May 6 2016, July 8 2016 and May 5 2017.

Follow Rob on Twitter @rob_keyes for your Marvel movie news!

Sources: Movies.com

Header art edited from poster by Matt Broox