A week ago SLAYER made it clear that they were in the studio working on a new album.

Little by little, details regarding their sessions are coming to light. Most notable thus far appears to be the revelation, via the photo below, that Terry Date is overseeing production for the effort.
 
For the unitiated, Date has been responsible for helming a handful of seminal works, including Soundgarden's 'Badmotorfinger', Pantera's 'Vulgar Display of Power', and Deftones' 'Around The Fur'.

Additionally, Date recently worked with Slayer for their single, 'Implode,' which was released in April.

The new album is tentatively slated for an early-2015 release through Nuclear Blast Records.