The problem with RNG is that guilds move on, and that's it. I've seen too many rogues move on to BT/MH without
[Warp-Spring Coil] or DST and are still using things like
[Bloodlust Brooch] when killing illidan. Badge gear was a step in the right direction in that your guild can progress to the next tier of instances, and even though your enhancement shaman never got any good weapons, he can buy the token fist weapons and manage to progress with the guild independently of drops.
The key idea that was posted not too long ago is a great idea, although I'm sure blizzard would never go for it. The same scenario would play out every time you run the instance.
3 rings drop: MT gets all 3 and he gets best gear he can out of the instance.
next week: OT gets 3 keys....
next week: Mhealer 3 keys
next week: other healers split keys for several weeks
some time later: DPS gets loot.
Why the hell would DPS show up if they're not going to get gear for 6-7 weeks? That would seriously blow, and it would be a worse system than what we have now. Now, that is an exaggerated system, but it would happen much the same with healers/tanks getting gear first, then DPS. But, I do somehow like it. Seems like a game show...
The system of getting tokens that drop for certain iLevel gear would be a better example, whereas Gruul/Mag/Kz would drop a "t4 prize" that is redeemable for all T4 gear, these prizes are awarded to everyone in the raid. But what happens if your guild moves on to T5 stuff and you're left with some weird combination of prizes that paralyzes you in terms of buying power? Also, this would mean that everyone raiding in the guild would get new gear at roughly the same time, and up until that point it would be slow going.
Roll elimination definitely sounds right on to me. A guild leader can eliminate 1-2 items from the table and viola, no more
[Pauldrons of the Argent Sentinel] or other trash that should drop twice then probably no more.