@all:
I did some testing on the target dummies tonight and found what I feel are some pretty conclusive results about specs:

1. Unholy single-target is about 6800-7k dps. I was able to get a really good mash button going that would reapply new diseases when I get a new target but otherwise would Scourge Strike and Festering Strike. The DPS spiked to 8k-8300 dps once the pets went enraged but that's not something you're going to see often in BG's and arenas I think.

2. Frost single-target was about 6k-6200 dps. I was able to fine-tune my dps setup and get a great mash button going that was equivalent to hand-running one of them as Frost. This however does NOT take into account the prevented healing from Necrotic Strike. Each NS I do is 6800 healing prevented. I get AT LEAST two per 10 second rotation, usually 3 based due to random rune resets from Frost Strikes. That makes another 13.5-20k "damage" per 10 seconds. Divide that down and you're basically doing 7.5k-8.5k dps on the Frost DK's to a target that's getting healing.

This is with ilevel 333 blue pvp gear and the CoC weapon against a single level 85 heroic dummy.

3. I tried out having one Blood DK/3x Frost and then one Unholy DK/3x Frost to see if the DPS went up across the board. The DPS went down with the Blood DK by a fair bit and it went down by a little bit with the Unholy DK.

4. I was able to work Hungering Cold into my spam button in such a way that I get all four of them usually in the first 15 seconds of combat but usually not all at the same time. It's insane.

5. Profit!