For the past two months I've been tinkering away at a site for automating PVE guild progression ranking (only US guilds right now). The problem with other guild ranking sites I've seen is that they always required someone to manually update their profile to say they've killed such and such boss. Using the World of Warcraft Armory I'm able to "just know" what bosses a guild must have killed. This method seems to be working pretty well, and giving results that I would expect both across my realm and the US (to the best of my knowledge). I know it's not perfect, but I believe it works pretty well.
So, here I introduce WowJutsu Guild Rankings: http://www.wowjutsu.com
My code updates the top 1000 guilds (and the guilds on my realm) every day, and other guilds through the week as possible.
I thought the people on these forums may be interested in some of the statistics I've gathered from the 10000+ guilds that I am currently ranking (You can see these on the site itself, but I'm posting them here for easy access and for those who may not care to even visit the site). These numbers represent of the 10000+ guilds how many have either gotten any kill in the given instance or killed a specific boss from the instance:
Karazhan 100.00% Rokad the Ravager 12.37% Hyakiss the Lurker 14.25% Shadikith the Glider 11.37% Attumen the Huntsman 99.01% Moroes 98.30% Maiden of Virtue 97.33% Romulo & Julianne 96.44% The Big Bad Wolf 96.63% The Crone 96.80% The Curator 92.59% Terestian Illhoof 65.95% Shade of Aran 80.65% Netherspite 52.31% Chess Event 90.94% Prince Malchezaar 75.49% Nightbane 54.14% Gruul's Lair 55.49% High King Maulgar 52.60% Gruul the Dragonkiller 39.00% Magtheridon's Lair 18.55% Serpentshrine Cavern 11.36% Hydross the Unstable 9.36% The Lurker Below 8.93% Leotheras the Blind 5.08% Fathom-Lord Karathress 6.49% Morogrim Tidewalker 7.33% Lady Vashj 2.47% The Eye 13.09% Al'ar 2.73% Void Reaver 13.06% High Astromancer Solarian 2.20% Kael'Thas Sunstrider 0.85% Hyjal Summit 0.75% Rage Winterchill 0.74% Anetheron 0.50% Kaz'rogal 0.26% Azgalor 0.24% Archimonde 0.14% The Black Temple 0.56% High Warlord Naj'entus 0.56% Supremus 0.53% Gurtogg Bloodboil 0.16% Teron Gorefiend 0.33% Shade of Akama 0.46% Reliquary of Souls 0.07% Mother Shahraz 0.03% Illidari Council 0.01% Illidan Stormrage 0.01% Doomwalker 7.21% Doom Lord Kazzak 9.41%