We at SMN have no idea how accurate these claims are so take the proper amounts of salt when reading this. A recent forum post on NeoGaf Forums claims to have some pretty huge spoilers for Batman vs Superman. This is coming from the users friend who was recently fired from the project due to it being pushed back 10 months. Take that into account that this maybe a disgruntled employee trying to get back at the company.
:: Possible Massive Spoilers ::
Here are the Plot Points:
The villians are Lex Luthor and Metallo
Batman forms a UN type deal to stop Superman from destroying another city
Aquaman is in it, but not called Aquaman. He's there because the world engine in the ocean did something to the fish
Jason Momao is definitely up for Aquaman
Wonder Woman poses as a Wayne Enterprises investor to retrieve an item that belongs to her people.
Lex Luthor is in the shadows a lot, a manipulator. Not much face time with Superman.
Robin/Nightwing betrayed Batman at some point, leading to a falling out between them
The Batcave was super cool looking, and the mobile looked similar to Burton's
Lois is investigating Lex.
Metallo "kills" Clark
The Daily Planet is bought by Lex Luthor for PR purposes
At the end Superman is living in exile, and the Justice League is an government approved superhero team.
Superman copyright battle won by Warner Bros. Heirs denied rehearing. 'Justice League' movie about to be fast-tracked?
— Nikki Finke (@NikkiFinke) January 21, 2014
Batman vs Superman hits May 2016