While Ramey claims that no Batman villains will feature in the movie, he does insist that Lex Luthor will play a role, along with a second Superman villain. He claims he cannot identify the villain, but that it's one that's been rumored (so--most likely candidates are Doomsday, Brainiac and Metallo, perhaps?).
Both Batman and Wonder Woman's roles are addressed in the post as well--and while it's mostly speculation, Ramey claims that he's hearing this is in fact a very Superman-centric film and that concerns of overcrowding should be taken with a grain of salt since the other characters will be comparably quite minor. To that end, he rejects the idea that Batman vs. Superman is really Justice League in disguise, and thinks it's possible or even likely that the eventual title will be Man of Steel: [Subtitle], to give
"Personally, I’d say it’ll be about on par with Scarlett Johansson’s first appearance as Black Widow in Iron Man 2. I believe that it’s a cameo-plus type of role that will (hopefully) serve as a springboard to a solo Wonder Woman movie," Ramey said. "With all that said, I’d bet a year’s pay – in MONOPOLY money, of course – that the 'Amazons' of this cinematic DCU will be descendants of those 'ancient Kryptonians' who attempted to set up Kryptonian outposts throughout spacedom thousands and thousands of years ago. Furthermore, I say that Wonder Woman will be powered-down, if you will, relative to Superman because these Amazons have evolved and adapted to living on Earth for hundreds of centuries. And since Kryptonians are produced without any 'He’n and She’n' – Jor El and Lara excluded – couldn’t this original Kryptonian on Earth have used this reproductive science to create an all-female race? I say yes!"
Ramey doesn't mention--or perhaps doesn't know--that Kara Zor-El--Superman's cousin Supergirl in the comics--was the one who crash-landed the outpost that later became the Fortress of Solitude in Man of Steel. This took place during the Wal-Mart exclusive Man of Steel Prequel digital comic, and it's not clear whether she or the villain who caused her craft to crash survived to fight another day.
He added that as far as he knows, there is no truth to the rumor that Wonder Woman will be Batman's love interest in the film.
For Batman, we get more specultation that the costume will be Kingdom Come-inspired, which jives with the drones and the Bat-robots that have been teased. With principal photography set to begin in February, Ramey expects a first look at Ben Affleck's Batman in the next couple of months.
Of course, take all of this with a grain of salt; it's a mix of inside information, speculation and industry rumor, from the sound of it--and there's more at the link above that I didn't include because these seemed to be the big bullet points, so feel free to read through and comment if you think something he mentioned in there is significant.