Since Patch 4.0.1, Abyssal Bag is now a BoE 22 slot bag usable by anyone. The abyssal bag was a warlock only bag that held soul shards. Since the 4.0.1 patch, they are now a cheaper to craft version of the glacial bag and the abyssal bag doesn't have a cooldown.
The glacial bag requires 4 ebonweave, 4 moonshroud and 1 eternium thread.
The abyssal bag requires only 4 ebonweave, 2 spellweave, and 1 eternium thread.
Learning The Abyssal Bag Pattern
The tailoring pattern requires revered standing with the Ebon Blade faction in Icecrown and is available from Duchess Mynx, the Ebon Blade quartermaster in The Shadow Vault. What if your tailor isn't your main and doesn't have the required reputation to purchase the pattern? Well the Ebon Blade Commendation Badges are only 16 Justice points each and award 520 reputation. So you may be able to top off that reputation with badges in order to learn the new version of the abyssal bag.