With the opening of the next arena season blizzard have issued a statement that resilience will be greatly buffed in a hotfix to dramatically reduce the damage players take in PVP even further.
It is most likely an experiment to help them decide how to handle the current "too bursty" pvp environment in which a global cooldown or two can be all that separates a player from a "safe" life pool to death.
The increase effect should be noticeable as an approximately 10% - 20% less damage taken, depending on how much resilience the player got.
Blizzard also stated they consider using other damage lowering methods for Cataclysm such as implementing an aura that passively reduces damage in all arena.
On a different note, the lich king encounter should be unlocked in about two weeks!
Till then, you can review the Queen Lana'thel tactics and the Blood Princes tactics pages. The Lich King Tactics page will be updated as soon as more info on the fight is relieased.