Batfleck, Ultron, Bryan Cranston and Vin Diesel: Superhero Casting News

The biggest—or at least the most controversial—recent news in superhero casting concerns the Batfleck uproar, but roles in other upcoming comic-book movies are being filled, too. Confirmed decisions and convincing rumors are filling in the empty slots on the cast lists of some big films, but none of the revelations have caused the kind of backlash that poor Ben Affleck has had to endure.

Affleck will, of course, play the role of Batman alongside Henry Cavill's Superman in the upcoming sequel to "Man of Steel." The news of Affleck's casting caused outrage among fans who apparently don't think that the Oscar-winning actor is fit to follow in the footsteps of Christian Bale—not to mention George Clooney, Val Kilmer, Michael Keaton and Adam West.

Fans are also likely to be unhappy when they hear that Bryan Cranston ("Breaking Bad") won't be playing Lex Luthor in the film. Cranston had been rumored to be a frontrunner for the role.

Joss Whedon's sequel to "The Avengers" made at least one definite casting decision last week. James Spader signed on to play the villain Ultron in the film. No word yet whether Spader will appear on camera or merely contribute his voice to a CGI character.

Less clear is the choice for an actress to play the Scarlet Witch, one of the most prominent new characters in the sequel. The top name in the rumor mill is Elizabeth Olsen (sister of Mary-Kate and Ashley), who moved to the front of the line when Saoirse Ronan ("Atonement," "The Lovely Bones") turned down the role.

Finally, Vin Diesel is reportedly in late-stage negotiations to provide the voice of tree monster Groot in "Guardians of the Galaxy."