There were cauldrons back in BC days that functioned similarly to a mage table. It required alchemy in order to drop one, but once an alchemist put one down, everyone in the raid could loot a potion off of it. IIRC, all of the old cauldrons only produced elemental resistance potions, but there was a separate item and recipe for each type of element, so it is not that far-fetched for Blizzard to make new cauldrons that do the same thing for combat flasks. Would make things a bit simpler for raids and for Blizz since they could reasonably balance bosses to expect that everyone is using their appropriate flask since there would be two ways to get each one.
My predictions on what we'll get:
* looted flasks are temporary items, so they get removed from your inventory if you are logged out too long (15min I think?)
* will probably provide either 25 or 40.. Possibly they will make it so each toon is only allowed to loot one from the cauldron to prevent people from getting multiples from each cauldron
* odds are good that it will require alchemy skill in order to use, at least until 2+ patches into the expansion
* STR&AGI (you get both stats, but one would be worthless to you depending on class)
* INT&Spirit (would make sense to roll the stat that gives mp5 into the flask with the stat that gives spellpower/mana since otherwise a pure spirit flask would see extremely limited use)
* Stam(plus armor maybe?) (happy tanks ^^)
** unlikely but would be awesome: magic/physical damage reduction, resilience, haste&crit, hit&mastery