The actual standalone game DayZ, not the ArmA II mod DayZ, was supposed to be out by now. It's not, of course, and won't be for a little while, but if you'd like an update on how it's going, creator Dean Hall has posted this 10-minute video.
A note: this is "raw, unedited...pre-alpha footage, so it makes no effort to mask the variety of bugs. Our whole focus is on getting the alpha out, which means focusing on Multiplayer (server) performance."
So take it for what it is.