Bornakk chimed in on a change to resilience that they are going to try and hot-fix in while we are between arena seasons:

We are currently in the process of applying a hotfix to buff resilience. While some modifications may be made, we intend to have this buff in effect for the remainder of the Wrath of the Lich King expansion.

The change will double the value of resilience in reducing damage done by players. So depending on their current amount of resilience, characters might experience a 10 to 20% decrease in damage taken from other players. The critical strike chance and critical strike damage reduction components of resilience will remain unaffected by this change.

We are also aware of the possibility that this change will make healing in PvP too difficult to counter. While we are not making any immediate changes to address this issue, we have prepared some further changes that will allow us to quickly deploy a PvP-only healing adjustment if we feel it is warranted.

We will be applying this change very soon while we are between Arena seasons so we can evaluate how it works in multiple PvP scenarios for the upcoming Arena season, and as we continue to prepare for Cataclysm. As we have mentioned previously, one of the goals for Cataclysm is to have a PvP environment where it is harder to regularly achieve so much damage and healing in relatively few global cooldowns compared to what we currently have in the game. (source)

There are still some maths questions left on the table... that bit about "The critical strike chance and critical strike damage reduction components of resilience will remain unaffected by this change" leaves me wondering if they mean "crit damage will still first be reduced by the flat damage reduction THEN reduced by the crit damage reduction" or if they mean "crit damage will still first be reduced by the OLD flat damage reduction THEN reduced by the crit damage reduction."

What's the difference?

Well, the latter example, it means that crit damage will not have changed. However, the former example has crit damage going down by a multiplicative ~10%.

I'm going to lunch right now... but more maths after the break.

OKAY, back...

At the moment, I have 1025 resilience in full relentless gear... my guess is that I will have more in Wrathful, but we'll have to wait and see. The point, however, is that I currently have 10.87% damage reduction from resilience, and 23.92% critical damage reduction.

Example Before Resil Change:
5,000 damage conflag.
4,457 damage after resil (10.87%).
10,000 damage conflag crit.
6,629 damage after resil (10.87% and 23.92%)

Example After Resil Change:
5,000 damage conflag (0 resil).
3,913 damage after resil (21.74%).
10,000 damage conflag crit (0 resil).
5,968 damage after resil (21.74% and 23.92%).

Anyway... as you can see, that's a pretty big damage reduction change... I'm wondering if playing burst isn't going to be a little bit harder once this change goes through and people start wearing 8/8 Wrathful (since going from 8/8 Furious to 8/8 Relentless was ABOUT 150 resil... we expect this to be the same... 1175 resil on a dps class, much?)