The previews unfortunately spent forever asking the same dull question. How is this a sequel to Prey? Where's the gravity puzzles, portals and spirit powers? They didn't focus on all the awesome features like agile-combat, pursuit gameplay or the parkour elements.
My friend was in QA on the game (he now works at Raven) and he said it was one of the best shooters ever made. You can take that how ever you like, but he isn't prone to hyperbole and he definitely doesn't have anything remotely like that to say about COD. Going by the gameplay though it certainly looks special.
The achievements leaked the other day (from a Steam pre-Beta build form late 2011).
http://www.aliennoire.com/home/news/p2-achievments/ - Spoilers!
The game was up and running on consoles and was 5 months away from being on store shelves, when Human Head stopped working on the title. Bethesda arbitrarily rejected their milestones (the same thing they did with Brink, Hunted and Fallout NV) in order to get Human Head to sign a new contract (Zenimax had accepted Radar group and HH's contract terms as is when signing the project in June 2009) with less favourable incentives for an independent. The reason we haven't seen the game is because while Bethesda own the content and IP, they don't own the renderer, megatexture tech and other in-house engine technologies that Human Head had implemented into ID Tech 4 over the course of a decade. Bethesda will have to deconstruct the gameplay and art and shift it to another code base.