EA has officially confirmed that Dead Space 3 will be getting a demo, and has also confirmed the release date for January 22 on both Xbox 360 and PS3.
The publisher has also said that, if you are an Xbox 360 user and sign up via the official website (which will require an Origin account), you will be able to get access to the demo one week early. So, if you have yourself a working XBLA account, it seems very foolhardy not to sign yourself up now. You will undoubtedly need that Origin account anyway to download the full game, so may as well net yourself some goodies.
As for the rest of us, we will just have to wait until January 22 to see what horrors await us in the Dead Space 3 demo.