As I said above, these posts are very helpful. What strikes me most of all, especially upon reviewing Grover's list of Abyssal layers, is how so many of us seem to have obsessive-compulsive lists of the same things. Personally, this sort of lore is 100% intertwined with my love of the D&D game as a whole, and is why I am unsatisfied with the modern FR and Eberron approach to the planes. I respect those approaches as unique creations, but when it comes to Dungeons & Dragons, give me the Great Wheel or give me nothing.
Ahem.
My own list lacked Salted Wound, layer 313, the Mind of Evil, and Malignebula. Here's one I've come across that you don't have on yours:
LAYER 313: UNNAMED (Abyssal eviscerators come from here; Miniatures Handbook)
Also, a couple of recent issues of Dungeon have revealed the identities of four Abyssal lords. They are:
LAZBRAL'THULL: Demon lord of torture and bloodletting. (Dungeon #122: Root of Evil).
MALGARIUS: A demonic plant that once controlled a layer of the Abyss, but which was defeated by the demon lord Lazbral'thull. (Dungeon #122: Root of Evil).
MALGOTH, THE: A "terrible entity" that ruled over several layers of the Abyss eons ago. Defeated by a consortium of seven demon lords, who led a fantastic assault on his haunted realm. The victorious demons scattered the Malgoth's essence across the Abyss, only to be deposed and ultimately destroyed by underlings on their home layers. (Dungeon #117: Touch of the Abyss).
THARZAX: Patron of poisonous things that creep and crawl. (Dungeon #123: Salvage Operation).
--Erik