Love him or hate him, GC took the time to get pretty involved in a discussion about DK’s success and failures throughout WotLK. The discussion was in the tanking forums and titled “3.3.3 Worked (sorta) for DKs” and can be found over at the official forums here.
Among the topics discussed was the population fluctuation of DK’s. First, they were “OP” according to GC, then they were fixed to be more inline with the other classes. This caused a lot of DK’s early on in the expansion, and tapering off later …

Quote from: Zarhym

I’m sure some of you noticed this in the 3.3.3 PTR patch notes:

Frozo the Renowned has moved into the Dalaran Magus Commerce Exchange and will be trading your Frozen Orbs for various other trade goods.

We DKs can again control multiple targets, with a hotfix allowing chains of ice to operate on more than one target. Should help in arenas, and the occasional PvE situation like Faction Champions.
This reverts an accidental nerf to chains which came in 3.3.

Blizzard just announced that Icecrown Citadel will be a staged release much like Crusader’s Coliseum was. It will be broken up into four separate sections: The Lower Spire, Plagueworks, Crimson Hall, and Frostwing Halls. The Lower Spire will be released first which includes Lord Marrowgar, Lady Deathwhisper, Icecrown Gunship Battle, and Deathbringer Saurfang so guilds can begin gathering information on these bosses for their 3.3 plan of attack. Blizzard has also announced that the final boss of each wing will have a limited number of attempts per week, much like …

Blizzard recently released a bit of a shocker to the raiding community the return of a Sunwell Radiance-esque type of effect with the raid-wide debuff Chill of the Throne.
To summarize for those who weren’t around in BC, or were around but weren’t party of the “Royalty” guilds of the time, a raid effect called Sunwell Radiance was introduced in the last raid of the expansion to shift focus away from avoidance and introduce more steady streams  of damage. (Gravity wrote about the change over at pwnwear.com and has the blue …