From the makers of Continent of the Ninth (C9), among a few other titles, this is Black Desert, the maiden MMO title from developer Pearl Abyss. As you can expect, Black Desert features a persistent open-world action missing from C9, while having the combat system in the veins of C9. Think active dodge, active block and various attack combination chains.
Large-scale castle/ town siege is 1 of Black Desert’s important features. Pretty much similar to those seen in movies, the defenders will have to destroy the invaders’ cannons, ladders and kill them off, while the invaders will have to destroy the main gate and try to climb up the walls. More strategic features will be implemented in due course to make this event as dynamic as possible.
Pearl Abyss is also attempting to make the economy of Black Desert a lively one, with players able to engage in various trade and production activities such as farming, factories (I am guessing metal crafting), properties, gathering and more. This will allow players to take time off the action and play the market to become more wealthy.
Black Desert has only been officially signed to Japan under publisher GameOn (which also signed ArcheAge Japan), with Closed Beta scheduled for early 2013. For a game which only started development around 2010, it is looking mighty impressive already.