My review of the Severed DLC (560MSP/$7USD, ~1.4GB).
Once you download it, you start a new game and there's a prompt for you to choose between DS2 and Severed.
Length: If you run through with no fear of things, it's not very long, but then neither was the main game if you played similarly. FWIW, I spent about 8H30M in Dead Space 2's story with mostly walking around and looking for everything. On my NG+ runs, I shaved that down to ~5H40M. Severed is two chapter's worth, and my first time through I took my time: ~1H30M. My second run was around half that.
Items, Weapons, Upgrades: You start off with the Patrol RIG, specifically made for Gabe Weller. It's nothing too fancy: 15% damage protection, +5% damage for Pulse Rifle and Seeker Rifle, 15 slots. There are some upgrades applied already, so you're not quite so naked. You also start off with 50,000 cR, a regular pulse rifle and a specialized Seeker Rifle with +5% reload & shooting speed. The workbench has a new function: after selecting something to upgrade, you can push Y (or triangle on PS3?) to remove all nodes (put back into inventory) at a cost of 5000 cR. There's no need to find schematics. Gabe Weller has access to the full range of weapons at the store, which makes sense. He's a security officer. Do keep in mind that Gabe Weller isn't an engineer so he won't be opening any node-locked doors either.
Level Design: Most of the two chapters are recognizable from the main story, but there are a few new areas. Each chapter takes place at different times from the main game, so it still feels different. I thought it was a bit fun seeing how the areas changed since before or after Isaac was there. Truth be told, I was hoping Severed might be longer and show more parallels with Isaac's journey. Ideally, they'd have come up with entirely new levels, but I suppose that's the path towards a new game. *shrug*
Gameplay: Heavy on the gun-play. Some nice surprises here and there. *shrug* It's Dead Space.
No engineering/telekinesis puzzles. No jumping around space either.
Story/Acting: Voice acting was pretty well done and on-par for the main game. I haven't played Extraction, but I still felt a little something by the end. The way it plays out is rather different from Isaac's situation, mostly because A) the damsel is alive, B) she's in distress.
Nothing mind-blowing revealed.
Replay Value: For some crazy reason there is no New Game+, which is bizarre considering that the saved game still mentions the current Round that you're on i.e. forever Round 1. So... replayability is basically... uh... other difficulties. *shrug* I was pretty disappointed considering I just finished DS2 for the 8th time. In Severed, there really isn't much cash for you to fully upgrade a weapon by the end, let alone two (unless you're on casual selling everything you pick up). It's not that you really need it, but why remove the option of NG+? I suppose you can find the new RIG and Seeker rifle for free in the store of the main game when you finish, something for the Hardcore runners.
Verdict: Disappointed mainly with the lack of NG+. That would have made the $7 much more appreciable for me. $5 would have been "ok" I suppose.
I'd like to see something leaning away from gun combat for the future though. The telekinesis and stasis have so much potential.