Cataclysm: Do You Know?

Tanking
Avoidance vs Stamina
If your health is always topped off by the healer(s), you need more stamina, to reduce overhealing and give healer(s) more time to react.

Otherwise you need avoidance if half of the time your health is not at 100%, to avoid/reduces physical damage.

Dungeons
Manual Invitation Does Not Grant Reward
Manually invite a friend to an in-progress random dungeon run does not grant him/her the run reward.

Quests
Shroud of the Makers (Uldum)
- Avoid drake, and walk instead of run under the stealth mode.

Tailgunner!
- Don't have to shoot down any plane to complete the quest, neither your plane will be shot down.