Unsurprisingly, I agree with Ancient wholeheartedly (except on the Zen part... I'm not that hardcore!)
I usually like the ID mechanic, myself. I think it's best when "formal identification" (identify scroll/spell/long use of an item) is coupled with "informal identification": throwing rings down a sink, dipping (such as POWDER's "you dip your hiking boots into the yellow potion. You gain insight on the item's nature: boots of water walking", that's brilliant, you just identified TWO items).
About being called a mioni-game, so far I'd only bestow that title upon DCSS: identification by amount (There's only one stack of potions that amounts to 6, that's potions of healing) and the "tried on a chicken leg" "tried by monster" notes really make it feel like a guessing game.
Still, it's not essential: IVAN is pretty damn nasty fun by itself, no need for ID'ing KTHXBYE. Mague Guild doesn't have regular identify mechanics - you always know what is what, you just don't know what some stuff does (charged bituminous wyrm scale? guess what it does? SPREAD TAR EVERYWHERE)
So far, for PRIME, I think ALL noxious canisters (=potions) have uses, except maybe one. Most of them can be used to recharge rayguns (=wands), and some of them have other uses.