The demo is available on Xbox Live and the Playstation Network. Definitely check it out. It's a parkour game where you have to scale buildings, run around skyscrapers, and evade police and SWAT units.
I played the demo last night and I loved it so much I played it about 3 or 4 times. It's like a first-person Assassin's Creed, only more realistic and much more involved. Stripping police of their weapons in slo-mo looks fantastic too.
The demo's ready now? Awesome. The previews for this look great and I'm planning on buying it when it comes out (in less than 2 weeks, I believe). I'll have to check out that demo when I get time.