Farewell anesthetic poison, we barely brewed you

When Burning Crusade was released the new rogue poison we got to play with was 'Anesthetic Poison' which had the unique property of doing damage without generating any additional threat.

The theory crafters out there soon realized that the reduced damage that this poison did compared to Instant Poison wasn't worth the lack of extra threat a rogue generated on the mob. This means that you'll generally find rogues running with Deadly Poison on the offhand weapon and (if they don't have a tame enhancement shaman) Instant on the mainhand.

It would appear that the devs at Blizzard have noticed that no-one is using it in anger and have left it out of the new Assassination talent 'Deadly Brew'. With two points in this talent, successful poison attacks have a 100% chance to apply a 2nd poison in the following way
    Instant -> Deadly
    Wound -> Crippling
    Mind Numbing -> Crippling

Notice anything missing, yep it's the black sheep of the poison world, anesthetic. Now the simple explanation is that this talent is from an alpha build and the final version of the talent will map anesthetic to deadly, in the same way crippling is applied based on the other two. Alternatively anesthetic poison was an experiment which hasn't appeared to work and is being dropped in favour of the existing five from the original game.

Personally I think this is a shame, and it would be nice to have some variety of poisons which could be used depending on the encounter. For 95% of the encounters I've played in game Deadly and Instant have seen me well. The only exceptions I can quickly think of are:
    High King Maulgar: Mind Numbing for taking down the priest (slows the heals to allow better interrupt chance) but switching as soon as he's down, or soon after.
    Terestian Illhoof: Wound poison, a full stack reduces the amount he heals himself from the sacrifice of a raid member.

Previous discussions have touted the idea of a corrosive poison which reduces a target's armor. However I don't think that this is likely when we already have an Expose Armor finishing move, and it would have to stack with warrior sunders else the tank is going to be disallowing it during the raid.

So with the present information at hand it seems correct to speculate that we'll just be getting new ranks of the existing poisons and the only major change is making them stack with Windfury.