Since patch 6.0.2 came out, I've rediscovered the love I once held for soloing older raids. More than rediscovered it - I've expanded it, because now I can pretty easily solo most Cataclysm raids (I'm working on Spine of Deathwing) and that broadens what I can gather for transmog. But it's more than transmog, and more than the sensation one gets when you push Rhyolith through all his phases so that he dies before he's even done yelling at you in an awesome parody of what it sounds like when I wake up.
In a recent interview with PC Gamer magazine, Ion Hazzikostas pointed out that one of World of Warcraft's biggest strengths is its depth of content. The MMO has been going for ten years. There are old raids and dungeons everywhere. It's not just old content - it's a resource. And it makes WoW a game with incredible potential.
One example is the module Return to White Plume Mountain, written by Bruce R. Cordell. It's one of my favorites because it takes the memories associated with that original (and excellent in its own right) experience and plays with them, expands them in some ways and contracts them in others, giving you a different experience that plays with the concepts from the original. Trust me, K-Imprints were badass concepts.
I bring this up because of all MMO's, World of Warcraft is the one that can come closest to this. We're about to enter an entire expansion that is basically this, in fact - the Draenor we're going to is an alternate reality, but more importantly, it's an alternate take on the same place we visited in Burning Crusade, and our experiences in Draenor will be shaped by the ones we had in TBC back in 2007. I remember feeling an overpowering sense of saudade (thank you, Portugal, for this amazing concept) when I explored Shadowmoon Valley on the beta, and its entirely because of the difference between seeing the zone back in 2007 as I approached level 70 and seeing it now as a level 91 - the feelings of excitement at something new leavened by the memory of what was, and can never be again.
It's not just the ability to create demanding memory that helps set legacy content apart, however. Nor is it the ability to mine it for cosmetic changes thanks to transmogrification. There are two other factors - the ability to inspire new content and the ability to be updated. The first is also implicit in the Warlords of Draenor design - similarly, raids like Firelands show how new content can be inspired from older content. There hasn't been a single-boss raid (Magtheridon, Malygos, Sartherion) that doesn't owe a debt to Onyxia. Every one of Mists of Pandaria's world bosses hearkened back to Azuregos.
One of the interesting things about raiding is, after a while, a lexicon develops between raiders, a kind of language based entirely in examples from earlier raids. One of my raid leaders began to describe every fight as Omnotron, to the point where we began to rib him for it. The older content became encoded information, a shorthand to help us get a grip on the current - remember X fight? It's like that. In essence, the legacy content becomes DNA, and each new fight, in its turn becomes legacy content that adds to that DNA.
Finally there's the update. Sometimes this works spectacularly, and other times one is left missing the content before it was updated - I still miss Zul'jin in the original Zul'Aman. I managed to solo it on a level 80 DK just before they pulled it from the game, so I still have a Jin'rokh, The Great Apocalypse in his bags. It's this last use of legacy content that concerns me from time to time - the update to UBRS has cost us something even as its given us something, and I sometimes wish that we could have both the original and the update, toggled in some fashion. But I loved the update to Shadowfang Keep, and I'm still on record as thinking the updated 40 player LFR version of Molten Core is brilliant - it won't be changed much and the original will still be there when the update goes away.
In the end, the sheer breadth of WoW is its greatest strength. Yes, we've been to a lot of places and looted a lot of corpses, but the legacy of all those raids is more amusement in our future.