Now I know there have been a ton of DK changes in the coming patch, not the least of which is HB being moved to the 51 point talent. It got me thinking about trying to get some of the best of both worlds of Blood's high health and Frost's high mitigation. I understand that AoE threat might suck with this build due to no HB, but maybe the new blood boil will make up for it. Please let me know your thoughts about: Talent Calculator - World of Warcraft
Honestly, the spec is very weak for a tank. In fact, it's pretty weak for dps, too. If you really, really wanted to go blood/frost hybrid for tanking, here's what I recommend: 30/36/5.
It is almost impossible to justify not taking Anticipation (unholy). 5% dodge is too good to pass on for a tank, it saves you a bunch of ilevel points, allowing for gems/enchants in other areas. Your snap aoe threat builder is going to be BB, so you need the points in Bloody Strikes (blood) to buff it as much as possible. Obliterate is going to be the main single-target big hitter, which is unfortunately mitigated by mob armor. And if you're looking for the mitigation of frost, you need to go down to UA for the extra CD. If you trust your healers and want to make their life a little more interesting, you could take the points from Anticipation and go down the frost tree to FS, giving you a better runic dump (than DC).
I wish you the best of luck; it's certainly a flavor spec, but just doesn't compare with the other options available.
My thought about anticipation was that the blood worms and improved blood aura would compensate in effective health, but I understand 5% dodge is a ton to just not have. I'm honestly not in love with this spec, but it just seems that it or a variation on it would have to work to give some survivability advantages.
Been thinking about this myself lately and would want some feedback on this build, 43/23/5, it's ment to use death strike(glyphed) instead of obliterate as the main big melee hit. It does obviously lack good AoE threat but its intended as a single target tanking spec.