People may already know this, but you can download the Timeshift Demo from Gamespot. Just started playing it, so don't have much to say yet. I will later respond with some more details, opinions, etc.
I was looking forward to this for the 360, so this gives me a chance to get a sneak peak.
http://www.gamespot.com/promos/2006/tim ... index.html
--Raz.