So, a lot of what we've heard about raiding since before Wrath came out was this concept of "Bring the Player Not the Class." Basically meaning that Blizzard doesn't feel it should be required to bring certain classes to each raid. For example, many of the Burning Crusade raids required certain classes (mage for sheep / steal magic, warlocks to tank, hunters to tranq shot, etc.) With almost everything in Wrath, they've pretty much eliminated that need. Only thing left I can think of off the top of my head is the MC'ing in Naxx for Instructor Razuvious on the 25-man version.
It's still held on a bit though, in a way. Ideally, the best way to go into VoA is to bring one of each class so that you're sure somebody can use a drop. Now, if they have it or not is another story, but still... it's not an instant-shard.
But I had this random idea for a raid. What if it took the complete opposite of Blizzard's statement. But not in a bad way. See.. what if there were certain mechanics that only a specific class could get the loot. Here's the catch though: the class-specific item is obtained by conquering that mechanic. An easy example would be that there's a lockbox (or maybe even a series of lockboxes) that contains either gold or a rogue item. Maybe there's a guy you have to MC in order to open something and then either gold or a priest item drops. (I mention gold so that you can still have Blizzard's precious "random drop" mechanic in play.) A mage can spell steal an NPC shield to bypass some lazer door. etc. You get the idea.
Ideally, it may even open some small wing or something so that you can only see that part of the dungeon/raid when you have that class. As a dungeon, it would almost make the run different every time based on what you brought to the instance.
Anyway, just a random idea disguised as a post on my blog. :)