On Xbox Live, the Gold members-only demo weighs in at a hefty 1.2GB, which you can queue up right now so the second you get home from your stupid job, you can turn on your Xbox and start pulling in those bits. And then you can start dismembering Necromorphs into bits. Already playing it at home? Well, keep it to yourself ... some of us have work to do.
[Update: The official Dead Space Twitter account says we should be on the lookout around 4pm. We're going to assume that's Pacific Time, where the Visceral Games team is located, and when the PlayStation Network update usually goes live. Sit tight!]