[Update: the demo is up on Steam right now.]
The polarizing Castlevania: Lords of Shadow is coming to PC soon as an Ultimate Edition, and according to Konami, the demo is hitting Steam tomorrow. While it isn't my favorite game in the franchise by far, I still enjoyed it for the God of War-like it was, and if you have a PC and haven't played it yet, I strongly urge you to give it a try.
If you're itching for the real thing, the full game will drop on August 27 with the two DLC packs in tow, and it's getting a European physical release on August 30.
Lords of Shadow PC [Joystiq]