Pretty sure these are the only things I have from 2012 so far, and I just got them last night, so I obviously don't have enough time invested in them to say anything substantial about them, but they've all given me strong first impressions.
Angel Witch - As Above, So Below
Aura Noir - Out to Die
Overkill - The Electric Age
Anybody that was approaching that Angel Witch album with skepticism...don't waste any time being skeptical. You're just wasting your time. Half of the album is pre-1984, but the new songs are great, vintage material as well, particularly "Geburah" and "Upon this Cord".
The first Zom demo has been the most exciting thing I have heard so far this year. It's been a while since I have heard something so truly inspired from these shores.
I thought the first song on Weather Systems was pretty fucking good, then I couldn't stand anything else. But that song is good enough to pick up the slack for the rest..imo. Alcest and Woods, Aborted - Hell yes.
Pallbearer, Napalm Death, Ignivomous, Charon, and Lunar Aurora. Dodecahedron, Mgla and Aborted were pretty good too, though I was a bit disappointed with the new Gorod.
Didnt know Profanatica came out with anything this year, gotta get that.
Barren Earth - The Devil's Resolve, Black Breath - Sentenced to Life, Orange Goblin - A Eulogy for the Damned and The 11th Hour - Lacrima Mortis are a few albums that haven't been mentioned here that deserve notice, particularly the Barren Earth one.