[Update: Aaron Taylor-Johnson is also unofficially confirmed for Quicksilver]

With Thor: The Dark World releasing in theaters next month and Guardians of the Galaxy in its final stretch of principal photography, next on the production slate for Marvel Studios is the flagship title The Avengers: Age of Ultron. The Joss Whedon written and directed sequel begins production early next year for a May 2015 release date.

And not unlike then next few chapters (post-Iron Man 3) of “Phase Two” of the Marvel Cinematic Universe, The Avengers 2 aims to expand the franchise by adding a few new characters. The brutally villainous Ultron takes center stage as the antagonist for Earth’s Mightiest and on the hero side, the roster of The Avengers will grow with the additions of Quicksilver and Scarlet Witch, a super-powered brother-sister act.

Nick Fury (Samuel L. Jackson), the mastermind behind the formation of The Avengers as a fighting force to protect Earth, made a cameo in Marvel Studios’ first foray into live-action television this week, in ABC’s Agents of S.H.I.E.L.D.. The episode-saving guest appearance didn’t help the show against a ratings drop of 34% from its premiere, but it did give the Wall Street Journal a reason to chat with Jackson who in turn confirmed one of the expected Avengers 2 casting choices – something Marvel Studios and Disney have been waiting on making official.

Not unlike the announcements of Bradley Cooper joining Guardians of the Galaxy and James Spader playing the titular Ultron in The Avengers: Age of Ultron, an official confirmation of Olsen joining the franchise will likely be made through Marvel’s own website, it’s just a matter of timing to separate out announcements for their upcoming projects. In the meantime, Sam L is doing the work for them:

“I don’t think we begin shooting before March of next year. I know we’re shooting in London, that James Spader is Ultron and going to be the bad guy, and that we added Ms. [Elizabeth] Olsen [who will play the Scarlet Witch], but I don’t know what she’s doing, if she’s on the inside or the outside. I haven’t seen a script.”

We previously reported on Elizabeth Olsen being in talks with Marvel and her interest in working with Robert Downey Jr., but nothing on the casting front is official. Olsen told MTV at the Toronto International Film Festival last month that she’d love to sign up but played coy as to the rumors of her being talks for the part.

“I’ve been rumored about lots of things [so] I don’t know… To be part of [The Avengers]? Sure. I grew up loving comic books and sci-fi… I think those movies are great. I would love to do something like that.”

 

Not only does the (magically powered) Scarlet Witch character need to be cast, but so does her (super fast) brother Quicksilver, who Aaron Taylor-Johnson has long been in talks for. Guardians of the Galaxy still needs to cast its Groot as well, a role Vin Diesel has been talking up since Comic-Con. Last but not least, director Edgar Wright revealed yesterday that he’s returning to Los Angeles after finishing his press tour for The World’s End to being pre-production on his long-in-development Ant-Man movie for Marvel, another project that will need to be cast in the coming months.

For more on Scarlet Witch:

Thor: The Dark World on November 8, 2013, Captain America: The Winter Soldier on April 4, 2014, Guardians of the Galaxy on August 1, 2014The Avengers: Age of Ultron on May 1, 2015, Ant-Man on July, 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: MTVWSJ (Hat-tip Nicholas)