4. The Joker Definitely Murdered Robin
For months, there were rumours that Batman v Superman would feature a scene of Bruce Wayne looking at Robin's costume on display in the Batcave. A nod like that to the comic books seemed unlikely, as did a reference to the Caped Crusader's young sidekick. Surely this dark and gritty DC Cinematic Universe wouldn't reference an arguably very silly character? For that matter, surely it wasn't so dark that the youngster was killed by The Joker in this reality?
Well, Robin's costume (which is still red and green, albeit very darker shades of both) is indeed on display, but with a twist. After murdering Batman's sidekick - who based on the size of this suit must have been late teens at least - The Joker left the Dark Knight a grotesque and taunting message on his body.
How the villain killed him will no doubt be revealed in the movie, especially if other rumours about a flashback are correct. It's worth noting that there is what appears to be a bullet hole beneath the chest, though it seems likely though that The Joker probably used a crowbar to take him out, just like in the comics.
Some fans have taken Bruce Wayne saying, "Twenty years in Gotham; how many good guys are left? How many stayed that way?" during and after the shot of Robin's costume as a possible indication that maybe the Clown Prince of Crime didn't kill Robin; he is Robin. Frank Miller's The Dark Knight Strikes Again (a sequel to The Dark Knight Returns) featured Dick Grayson - the first Robin, not the second who was murdered by The Joker - being revealed as the new Joker, so there's precedent in the source material for this happening...