with the changes from the PTR I am looking for a way to max out all the tanking talents. I am just not convinced that Frost is the end all be all. I think the above spec gets some great skills from blood and Unholy.
1) bone shield +glyph, even with 2min CD it still better then UA
2) +6 magic reduction and AMS whats not to like there.
3) 10sec faster death grip
4) 15second DnD EVERY DK tank has to have that .
5) 20% stun/fear reduction
6) Unholy Blight is a nice agrro draw when DnD is down
7) 5% dodge again one every DK tank takes.
1) blade barrier is getting changed to 5% damage reduction so i assume that is all damage
2) Rune tap and IMP Rune tap whats not to love about healing yourself for 5k every 30seconds
3) spell defection same chance as your parry rating to reduce spell damage by 45% that amazing
4) +6% str AND sta thats extra HP and extra PARRY!!! see #3
So thats my thoughts I think it beats out any "plain jane" Frost tank spec..