Here are some Trees I came up with

[Quickslay]

I use to be a Deep unholy tank ever since I got to northrend..... since 3.1 release I havn't tanked much but did notice I do take much more hit..... go go blade barrier nerf(grumble)

I've been playing with the trees and came up with a few different specs

Unholy/Frost
5/24/42

Unholy/Blood
24/5/42

Blood/Unholy
50/8/13

Blood/Frost
41/23/7

Deep Frost
5/56/10

Frost/Blood
25/36/10

Frost/Unholy
5/37/29

I really don't know about the Frost/Blood or Frost/Unholy specs.

Here is my DK's curent spec Ñemesislayer that is also missing Frost presence 29888hp unbuffed
Any help would be good