There's quite a bit of info revealed in the official announcement trailer for Dead Space 3. Series hero Isaac Clarke is joined by potential love interest Ellie Langford from Dead Space 2 and a new character named John Carver. John was introduced in the Dead Space graphic novel short less than a week ago.
John is a soldier with a marriage on the rocks. He appears to be working with an entity that is either in charge of or contributing to the construction of the markers. When introduced to us, John is working on the planet Uxor. When the shroud covering the marker comes free, it unleashes an EMP that brings ships plummeting from the sky. With horrific crashes come dead bodies. The marker then takes those bodies and turns them into a fresh batch of necromorphs.
With Dead Space 3 taking place on the frozen planet of Tau Volantis, there may be some uncovering of John's past that needs to happen. At the beginning of the debut trailer, Ellie mentions that they have the opportunity to stop this at the "source". This could mean a few different things. Is this the source of all the markers? A master marker of sorts? Is this the headquarters of the Unitology fanatics who are responsible for creating the markers?
What is known is that Isaac and John are separated from Ellie early on in the game. Ellie appears to be Isaac's driving force in this game with the destruction of the markers taking a back seat. This isn't shocking as Isaac spent the better part of two games getting over the death of his past love, Nicole.
The gameplay demo focuses heavily on the puzzle elements of the game. There are some necromorphs to shoot, but there's not a whole lot that's new...until people start shooting at Isaac and John. Sure, Isaac had to fight a few other humans towards the end of Dead Space 2, but depending on what this "source" is, he may be facing more enemies than just necromorphs.
Dead Space 3 is scheduled for release in February 2013. It will make a perfect Valentine's Day gift should we survive the apocalypse of 2012.