Holy surprise casting news!

Twitter lit the Bat-Signal Thursday evening when news broke that Ben Affleck would take over the role of Bruce Wayne from Christian Bale for 2015's "Man of Steel" sequel, starring Henry Cavill.

The pick was an unexpected one, to be sure, considering the reported short list for Zack Snyder's follow-up (rumored to be titled "Batman Vs. Superman") didn't include Affleck, but actors like Ryan Gosling, Josh Brolin and Joe Manganiello. (Not to mention some were holding out hope that "Dark Knight Rises" star Joseph Gordon-Levitt would return to claim the cowl.)

Reactions via social media were swift and divided, with #Batman, "Ben Affleck as Batman" and even Michael Keaton becoming worldwide trending topics. From sentimental to snarky, here's the best of the Batfleck banter.

No one seemed quite as enthused as super-geek and frequent Affleck collaborator Kevin Smith:

Except maybe Snooki:

With So Many Different Versions Of Batman Out There, What Kind Of Caped Crusader Will Ben Affleck Be?

Some were sad they had been passed over for the plum role:

Others reminded us that Affleck is no stranger to his foe:

(If you're wondering where that image came from, Affleck played "Adventures of Superman" star George Reeves in the 2006 drama "Hollywoodland.")

And then there was the requisite parody account:

And the memes:

And speaking of Matt Damon...

And the ones that we just couldn't help but giggle over:

Who has yet to weigh in via social media? Affleck himself, whose most recent tweet as of press time was dated August 5.

"Batman Vs. Superman" is due in theaters July 17, 2015.

What do you think about Ben Affleck's casting as Batman? Sound off in the comments!