http://www.shacknews.com/onearticle.x/50709
They’re bringing back badlands, which I don’t really remember, but a lot of the original maps were class 🙂 There’s also some change to the medic’s play, with them saying
“It’s a large scale modification to the core of the game,” Walker hinted. “It’ll debut in a limited fashion through the Medic first, but it’ll be affecting all classes eventually.”
As to what it might be there’s been nothing else said, but someone has come up with quite a clever interpretation saying that this could be a return of infections 🙂 “Affecting all classes eventually” being a pun.