That's well and good but there are almost no mobs that use poison in the game ATM , maybe with the update we will see more .
Current state, you are correct. Will be interesting to see if the new mobs have poison. The description of several certainly allow for poison: Smugglers are Rogue-like from their description, "reptilian Warbeasts," spiders, scorpions, lizards and snakes.
When I wrote my post, though, I was actually thinking that every bit helps in the arena. I am lucky there is a floor to PvP levels... otherwise I would be in the negative ranking...
Maybe sometime in the future, they could be of great use if a piece of equipment were to be released where effictiveness increases as your percentage of health decreases etc. I'm just pullin idea out of the top of my head.
It would be interesting if they coded consumables into high level skills. A high damage Rogue poison skill that requires a Deathcap to cast, for instance.