WoW Jutsu has an automated solution. This site tracks raid progression by scouring the Armory for players with equipped raid drops. It accounts for players with raid equipment who move guilds, but can't account for joint raids, yet. Not a perfect system, but a usable one for automating an otherwise time-consuming process.
The site is well designed with a clean look (important for an information site.) On it, you can track by realm or see game-wide statistics. The owner also provided a well-written FAQ explaining how the rankings are compiled and what to do if you feel your guild's listing is inaccurate.
WoW Justu is also good for seeing how much raid content has been finished world wide. For example, less than 2% of the guilds tracked have entered the Black Temple, but almost 66% have finished Karazhan. It will be interesting to see how much raid content is finished before the Wrath of the Lich King expansion goes live and another set of content becomes obsolete.