Clue 1: Freaks dressed up as Clowns
I was watching the trailer for [Batman v Superman: Dawn of Justice](tag:711870) and something caught my attention: Bruce says to Clark:
"Maybe It's the Gotham City in me. We've had a history of freaks dressed up as clowns."
I realized that he might be hinting a reference of the Joker. All the fighting takes our attention away from that.
Clue 2: HAHAHA JOKES ON YOU BATMAN
Also in the trailer there is an image that says HAHAHA Jokes on you Batman. That just screams Joker. Plus there is a Robin logo on the suit so maybe even Robin is gonna be in that movie.
Clue 3: Jared Leto
I saw an image of Jared Leto as the Joker and he has like an x on both his shoulders so does the suit above.
Clue 4: Keep Calm and Call Batman
There is an easter egg in Man of Steel that is a poster which says: Keep Calm and Call Batman. Batman must be introduced BEFORE Man of Steel.