Dark Souls (ダークソウル Dāku Souru) is an upcoming video game being co-developed by From Software and Namco Bandai Games. It was previously developed under the codename Project Dark and is the spiritual successor to Demon's Souls. Dark Souls is planned for release on Xbox 360 and Playstation 3 by the end of 2011.
The game will focus on dungeon exploring and the tension and fear that arise when players encounter enemies in this setting. The game is a spiritual successor to the Demon's Souls (which is a spiritual successor to the King's Field games). The player will battle using various weapons and strategies to survive in a dark fantasy world. Online features will allow players to share the play experience without need for direct communication.
There will be more weapons, spells, and no classes. It is also said to be 'significantly harder', with more enemies and more difficult encounters. It will include leaving messages to other players, seeing others' deaths, and player versus player as well as a new co-op system.
Source: Wikipedia, "Dark Souls," available under the CC-BY-SA License.