At Sony’s keynote address yesterday at TGS, From Software revealed what appeared to be some sort of follow up to its hit RPG Demon’s Souls. The title, Project Dark, is not a sequel to Demon’s Souls, but it's for fans of the game.

At the keynote, the game appeared to be a PlayStation 3 exclusive like Demon’s Souls, but that does not appear to be the case outside of Japan. The English version of Project Dark’s website lists Xbox 360 as a platform with the PS3, along with logos at the bottom of the page. Interestingly enough, the Japanese site does not include the Xbox 360 logo and branding, likely because there is not a huge Microsoft market in Japan.
Project Dark apparently headed to PS3 and Xbox 360 | Joystiq

Sony owns the IP for the Demon's Souls game, so while this looks similar, it's not a direct sequel.

Here's a link to the video clip:

YouTube - Project Dark