The Deredeo Dreadnought has been revealed today for pre-orders on Forgeworld. It has seperate weapons detachments that have to be bought separately, and the experimental rules for the new Dreadnought are already up.
Here is a link where you can order it, and the rules are linked below.
via Forgeworld
The Deredeo pattern dreadnought is a dedicated heavy support frame, though it shares many core components and systems with the more general assault-based Contemptor class. Initially deployed in limited numbers to each of the Legions due to difficulties in its manufacture, its durability and firepower saw demand for the Deredeo pattern dramatically increase after the outbreak of the Horus Heresy.
One of the primary weapon systems the Deredeo can mount is the twin-linked Anvilus autocannon battery, a fearsome development of the existing autocannon pattern that can engage and destroy armoured targets with a punishing salvo of fire. The carapace of the Deredeo can also mount additional weapons and support systems, including heavy bolters or heavy flamers for close-in defence as well as the advanced Aiolos missile launcher which, with its sophisticated targetting system, can track targets independantly of the primary weapons system and regardless of intervening terrain.
The Deredeo Pattern Dreadnought is a multi-part resin kit which includes the sarcophagus-mounted heavy bolters or heavy flamer options and an 80mm plastic base. The Anvilus autocannon battery and Aiolos missile launcher are multi-part resin kits which are sold separately. All are available to pre-order now and will be despatched from Friday January 30th. The Aiolos missile launcher shown in the painted images is a pre-production model. Experimental rules using the Deredeo Pattern Dreadnought in games of Warhammer 40,000 and the Horus Heresy can be found here
http://www.forgeworld.co.uk/Downloads/Product/PDF/D/Deredeo.pdf