According to an interview with Rolling Stone Kerry King states Slayer have already begun recording their new album slated for release in 2013.
The band already have two tracks completed and are now awaiting mixing. "Two additional songs require vocals, and another two were created as demos with producer Greg Fidelman, who worked with the metal band on 2009’s 'World Painted Blood' ".
He also mentioned he'd like to get back to work after Mayhem Festival on August 5th in Hartford, Connecticut is finished. "If I get off my a-- and start writing again on the road – since we've been in Europe, I keep trying to work on lyric ideas, maybe some leads, and fixing songs that didn't work correctly – it should be a real quick process."
As far as whether Jeff Hanneman will return to Slayer due to recovering from "flesh-eating necrotizing fasciitis", King told Rolling Stone: "We're planning for him to come back and the door is open, because it's his f---ing gig. If he can play, Jeff Hanneman is going to f---ing be here, and I'm stoked about that. I love playing with Gary, and he's doing a killer job, but if Jeff came back and said 'I'm ready,' I'll check him out to see that he's ready, and off we go."