Raid Challenges

You can only complete one raid challenge a week. So, this achievement will take a guild at least 50 weeks to complete.

That's pretty insane...

For what it's worth, these are NOT completable in level 80 raids at 85 (even though the mobs are still green). Just tested on OS3D 10man.

In other words, this achievement requires you to raid for a year, killing at least one Cataclysm boss per week. Baradin Hold bosses count, assuming you have at least eight guild members in the group. In a year or so, this achievement will be an excellent measurement of how reliable a guild's raids are. Any guild that can get a raid going every week will get this without even trying, while it'll be out of reach for all other guilds. It will be an easy way to check if a raiding guild is likely to be able to deliver on what they promise, assuming they've been around for a year or more.