This image is taken straight from Forgeworld, just so you all know.
He's the new Chaos Sorcerer of Nurgle that they've added to their line, and you bet your bottom dollar that I ordered one. He's going to act as either a Sorcerer of Nurgle, or as a Lord with Mark of Nurgle and a Daemon Weapon.
This model looks sweet as hell, and I'd encourage anyone with a love for Chaos Space Marines or, more specifically, Nurgle Marines to go order one. He's currently going for £10.00 (about $20.00). You'll find him listed on their "New Stuff!" page here, along with a new Nurgle Dreadnought too.