According to one source, not only will Baker finally become The Lizard in Spider-Man 4, but we'll also have to contend with a certain villain known as Carnage. Spider-Man 4 would have to go a little bit "darker" than its predecessors to accurately capture the Carnage story, which focuses on a serial killer called Cletus Kasady who comes into contact with some of Eddie Brock's "symbiote" goo while they're both stuck in prison. (Connors, on the other hand, becomes Lizard after injecting himself with reptilian DNA in an effort to re-grow his missing arm.)
FreezeDriedMovies.com claims that these scoops come from the same source that gave them the Venom scoop a while back, so hopefully both villain reports are accurate. Apparently there's also talk of getting Black Cat into the Spider-Man 4 mix, because if a record-breaking opening weekend tells you one thing, it's that you can never have too many villains in your Spidey sequels. (Perhaps we'll get some of the goofier villains -- Rhino, Vulture, Electro, Kraven the Hunter -- in Spider-Man 5.) Plus, wasn't there a set-up for the Man-Wolf villain in Spider-Man 2? I can hardly keep track at this point.