I was never a "Vanilla WoW" player, and so I never got to see the vast majority of the raiding at that level. I sortof saw patches of stuff, and I even got to wipe on a world dragon a few times. Having not seen all this content, and having gone through most of the quests and very thoroughly through all of the instances I've come to appreciate the stark contrast between Vanilla and everything since.
I wonder if the difference is because a number of key people left Blizzard to do their own thing. But looking at that press release, it looks like only developers left. The art and design of Vanilla itself has a level of detail that is completely beyond what it seen since. The complexity is much much higher.
I think two things could be argued.
First is that the efforts which were put into Vanilla were redirected to other games, and Vanilla and its expansions were left to rot without decent input. This is pretty reasonable. We see only a touch of new stuff here and there, and throughout we see blatant re-use of ideas. Anyone who has done 70s instances and raiding who gets into 80s instances and raiding will see the exact same things done over and over.
Second is that Blizzard made a higher-level decision to "tone down" the game. This is also reasonable, since they have explicitly made many changes to baby their players. One-path instances, short-duration instances, removing attunement, more xp, earlier mounts, optional mount quests, the revised LFG with cross-server character matching and instance-teleportation and probably more.
Since all of that 60 and 70 "end game" content (instances and more) is still there, it's reasonable that players would choose to not purchase an expansion so that they can continue to have fun with that stuff.
Now that XP-locking is possible, a player can have the latest WotLK expansion and choose to turn off XP when they reach either 60 or 70. Or maybe 60 for a while, and then 70 later on.
This leads us to guilds dedicated to "oldschool" content. Aah yes, my existing readers will recognize my use of that word. Yes, it looks as though Vanilla/classic/Pre-BC/BC content is now the "oldschool" of World of Warcraft.
I haven't seen much level 70 stuff out there. It seems that this content is just being raped by level 80 people who are merely achievement whoring.
But for level 60 content I did run into some interesting stuff. If and when I find some more I'll update my lists.
http://level60love.com has a pretty obvious focus. They support the continued use of classic content.
They also created
an online petition for a level 60 pre-patch server (archived). This reminds me of the significant outcry when Star Wars Galaxies was updated and the gameplay was completely altered. Petitions were made, and the userbase went so far as to re-create the whole thing from scratch as SWGEmu. What did that game developer do? Not a whole lot. I suppose they didn't want to compete with their eventual release of Star Wars: The Old Republic. Which I will probably be playing when it comes out.
level60love also maintains a list of classic content raiding guilds whose guilds I have not completely explored, mainly because this list does not answer a couple of basic questions: Is the server PvP, PvE or RP?; What is its time zone?
One guild that I have noticed is Screams of the Past. They are an Alliance guild on the PvE Drakka server, which is CST. They have a very large character and player base, raid actively and have very active forums. They also went out of their way to detail all of their rules and regs, which is extremely appealing to me.
Having thought of all of this and seen what's been organized, I'm quite tempted to get involved. However, there are some things which I want to do first: Organize my existing guild activities; outline my "perfect guild" (update: The Perfect Guild (for me)); write up my guild activities ideas; and write up my levelling guild ideas. Some of these things will be pretty easy to do and I've already done a significant amount of work, others will be done over time.
So in the meantime I've created a World of Warcraft-Guild category to house whatever comes out of my brain.
(edit: That category must have been dropped during migration)