More Blue Post from Blizzard about WOTLK situacion ( class balance, raid issues, Boss encoeunters)
amost the blue posts/GM threats you can find some changes as:

Debuff Limit:
We changed how the game handles debuffs (ie negative state effects on targets) on creatures with Wrath of the Lich King. The old hard cap of 40 debuffs on a target no longer effectively exists. You can now apply way more debuffs to a target without them dropping off before their duration expires. The default WoW UI will not normally display all these debuffs, but they really are still there![Daelo]""

Ulduar Difficulty:
Ulduar will be harder. It still might be do-able by more than the most elite 5% of players, but it will be a lot more challenging. And we'll continue to have "hard modes" that are even more challenging. We'll make sure some of these challenges offer appropriate rewards.

Class Balance In Relation o Easy Content:
We knew we were messing with class balance quite a bit, so it's nice that things are a little easier right now. It gives the players time to learn the new spells and abilities and gives us a chance to see how things really work out in the actual game with thousands of people beating on the mechanics. We'll continue to make adjustments as necessary. It's an MMO. Things change over time.

To see the whole posts +DK changes:
http://www.worldofraids.com/

In 10 man raids that cap limit was never really reached ... nor in 25 man raids

Thats what i though, but thats a gm article from today XD( well yesterday actually XD)

CoA - Corr - Siphon - UA - Haunt - immolate - ISB - SE

take 5 affliction warlocks to a raid and they will reach it by themselves :P