eventually I believe they will be used, but will as for now, like many systems in the game, they are broken.
One gm said they were under the impression the Fatal Concoction will be 100%, not 1000%, therefor its possible with debuffs, or losses from armour to not have a fatality, but more likely than not, still do one. But they made sure to cover their asses and say that its only speculation on their part and by no means is the voice of what will be.
:p
It does seem a bit more normal than a level 20 pot that ALWAYS does a fatality.
As for the others, to me, it would seem they will be cool emotes, or effects, like you see in other mmos such as Guild Wars and WoW.
I only just found drinking works with the Ambrosia (or w/e) from the bar at the docks in OT. Previously I didnt think they worked.
Although, the animation makes you slide while looking tipsy, no awkward walking or running.
