Bael

I wouldn't be so quick to discount the possibility of different 'levels' of difficulty for the same instance. Bear in mind that the raiders who are interested in competing in the first place are going to want to take on the challenges of raiding in their most difficult form, and adding prestige or vanity items to encounters completed on 'Normal' or 'Hard' mode would be an effective way of delineating between the 'casual' and 'hardcore'. The items the boss drops need not be changed in any significant way; a slight increase in item budget, as well as some additional flavour text, weapon effects, titles, or simply increased gold or Illidari drops would be pretty significant motivation to try and take on the harder incarnations of a boss.

For the average guild breaking in to 25 mans, being able to complete instances on 'Easy' would give them a chance to experience content that they would otherwise only see in videos. While it should still provide a challenge to that kind of guild, and require a certain degree of individual performance and raid cohesion, it should be forgiving of mistakes and educate the raid on how to learn boss abilities and adapt to dynamic encounters. Low numbers of trash, long respawn timers, reduced damage from abilities, longer enrage timers, lower hp pools. An easy level Mag would have no Mind Exhaustion Debuff, easy Leo would have a leash on his whirlwind, easy Archimonde wouldn't Air Burst. Across the board, a guild would be able to experience all of the game's raiding content at a level that is challenging for them, as a raid, to complete.

You could tie these Easy-level raids in with the lore, thanks to the timeless nature of WoW. In Easy incarnations, the forces of Shattrath have finally managed to penetrate into the heart of these evil lairs, and assist the raid in the form of buffs, debuffing and damaging bosses, and generally making up for what the raid lacks in skill, execution or gear. Serpentshrine Cavern has been assaulted by the Cenarion Expedition, and as such most of the trash is locked up fighting druids and trees: Doomwalker has breached the Black Temple and engages in an epic battle with the Illidari Council, diverting attention from the raid group. In Normal level raids, such NPC assistance would be absent, and in Hard incarnations the opposite will have occured: dead Draenei and Blood Elves litter the corridors of Hard level raids, with their weapons and energy being used against the raid group.

The beauty of Hard incarnations is that they could be tuned for the absolute bleeding edge, and then some. Got all of your shiny Sunwell epics from Normal raiding? Why not go back to Gruul, who Grows ten times faster and at each Grow, reduces incoming damage by 2%. Try out a Void Reaver who's Orbs have a 40 yard radius and hit for 15k. Make the trash hit impossibly hard, and make the bosses hit harder. Make the content virtually impossible to clear, and give all of the raiders who cry out at the lack of content something to really bang their heads against. And if they manage to defeat these super-incarnations of BC bosses, reward them accordingly; unique buffs, unique pets and tabards and mounts and whatever other crazy indications of power and glory the itemisation team can come up with.

Hardcore guilds could use Normal raids to hone their skills and Hard raids to execute them. Casual guilds could use Easy raids to whet their appetite for content, before going back to struggle through Normal T4. And since Blizzard's inclination as of late has been to let every man and his donkey have access to the ultimate in epic gear, the loot tables need not be altered in any significant way: maybe take the Warglaives off Easy Illidan, and give it to the Normal incarnation, while an Illidan killed on Hard has a chance to drop the 'Infused' Warglaives, with even more demon-killing goodness. Nerf the best items so that guilds can't farm their 'best in slot' gear from Easy raids alone: while they won't be replacing their T6 Easy epics with T4 Normal ones, there would be a stigma attached to an 'Easy' Bulwark, which has reduced armour compared to the 'Normal' version.

I guess that I see the introduction of different 'modes' in a raid as an elegant solution to the topic at hand: 'suiting' instances to different, competing groups. As long as there is always a wall for hardcore raiders, there will always be competition, and having Hard raids brings up a whole range of possible rewards for who kills the bosses first, who kills them fastest, who kills more and who wipes the least. You could incorporate that into the 'week by week' standing that we are familiar with in Arena; register a raid group of 40 people, and track your progress against that of the rest of the world.

And all the while, the casuals get to play in their kiddie-pool raids, wetting their feet in watered down boss fights and playing with their epics, oblivious to the fierce competition at the pinnacle of the raiding game.


Edit: Sorry about the wall of text