I have been reading these DK threads for a while now and picked up a few tips, so I thought I'd lend some help with 3.1 Frost DPS. For the past few days I've been testing several dps specs in EACH of the three trees and have found Deep frost to be overwhelmingly better than both Unholy and Blood... by a margin of nearly 600 dps. Partially because I have been raiding 21/50/0 for ages.
Rotation: IT, OB, BS, BS, Blood Tap + OB
FSx4, BS
ITx4, FSx2, ITx2, FSx2
After that it's Priority to keep Death Runes up.
I used this same rotation for ALL of the following tests, Minus a FS here and there from Buggy RP.
Here is a Screenie of the normal Frost (Now 20 / 51 with moved HB) build I use to raid. Glyphs are Frost Strike, Icy Touch and Obliterate.
Rotation: IT, OB, BS, BS, Blood Tap + OB
FSx4, BS
ITx4, FSx2, ITx2, FSx2
After that it's Priority to keep Death Runes up.
** Note that BotN seemed a bit buggy and didn't always give me a Death rune. In addition, Glyph of Icy Touch and the 4 piece set bonus for Obliterate were not awarding the proper RP so I was getting one, sometimes two less FS per rotation. **
I also tested a Frost / Unholy spec to include Necrosis, Ghoul and Blood-Caked weapons. Glyphs were Obliterate, Frost Strike and Ghoul.
I had recount show pet also, separated from my own dps. Add the two for total. Without DRM from blood I found I was waiting too much on rune cooldowns in Unholy Presence. Here is the same spec (with pet) in Blood Presence:
Combined DPS is much better in Blood and the Runes seems to be available when needed much better.
Overall, Frost still seems pretty powerful to me and I will continue raiding this spec when 3.1 is live. As for Pet / No Pet, that comes down to how fast will that sucker die without NotD. Also, with RP bug from 4 piece Set bonus, IT glyph and BotN not working 100%, I think the actual dps will be HIGHER than what I tested since there will be less downtime and more specials being spammed! Hope this info helps some of you in testing more Frosties.