The Frost build I was going to use before going Unholy was
this.
How it differs from yours and why I think it works better:
3/3 Subversion--9% Crit on Oblit is pretty nifty for single target fights. And, sometimes, you want to lose threat to another tank so the Threat reduction in other stances can be nifty.
0/5 Icy Talons--I don't know what you will be running. This may or may not be useful for you. In general, the common consensus seems to be to bring a Shaman in possible, because it does a better job and costs no talent points. Plus, Haste isn't that important for 2-Handed DKs (at least as tanks, and except maybe for Blood DpS, but I'm not sure).
0/1 Icy Talons-- Same as the above. 5% to us isn't that great, and a Shaman works better.
[NOTE] If you will be running 5/10 mans, this MAY be a good choice, because it can boost certain class' DpS by a decent bit, and you are less likely to have someone else with it. Even still, I might keep a second spec without it until you get into 25 mans, just in case.
0/1 Lichborne--Just a PvP talent now. It has MINIMAL PvE use. And, depending on your race, the racial may cover it.
5/5 KM--Having a crit 90% of the time you HB is pretty damn sexy. Plus, it boosts your Frost Strikes and ITs on single-target fights.
2/2 Chill of the Grave-- More RP is never bad. This will equal 10-20 additional RP per cycle. So 1-2 additional Rune Strikes or 1 additional FS.
2/2 IFP--2% damage reduction. It may not be anything special, but that will be thousands and thousands of mitigated damage over the course of an instance.
0/3 Morbidity--If you are really having AoE problems and need to lay down a DnD every cycle, take it. But, the threat from HB should be similar, depending on your AP. And, this will open up your rotations for rotating Oblits/ and 2 (maybe more) BBs in AoE situations. You don't use DC, so that 15% is lost on you.
2/2 Epidemic-- A lot of people disagree here. On AoE fights, they pretty much win. Your HB, when glyphed, will cause FF, and that is all you should need after the initial IT and Pest. But, for single-target fights. Using all your runes, assuming you Oblit 3 times they second CD, you will only have .5 seconds left after you finish your third, so you risk losing the disease bonus if that third one gets delayed due to a stun or lag. Plus, your FSs will not be getting the 20% bonus from FF. Just seems wiser to take it, to me. The only other place I could think that is better for those points is in 2/2 Merciless Combat when ONLY considering enemies with 35% health or less.
Glyphs I picked and Why:
Obliterate-- 20% additional damage to our main, rune, single-target threat ability? Hell yes.
Howling Blast-- If you are only going to be tanking bosses, there are better glyphs. But, this one makes your AoE rotations pretty damn special. Removing IT from your rotation after the initial one basically means an extra Oblit or 2 additional BBs the entire fight instead. Doesn't do anything in Single-target situations, though, except refresh your FF on Rime procs.
Unbreakable Armor-- HIGHLY debatable. Once you get better gear, the addition to mitigation becomes smaller and smaller. Even when less well-equipped, there may be others. I was gonna test it out, to see if I liked it.
Other choices (to replace UA, and maybe HB):
Rune Strike-- I haven't heard good things about this glyph, but it is still an option worth investigating. I don't recall why it was looked down on, but worth checking out if you are interested.
Hungering Cold-- I would ONLY take HC if you were willing to take the glyph. 40 RP is a pretty hefty cost, imo, for an ability that doesn't offer much mitigation (in a Heroic AoE context).
Frost Strike--Some people swear by this glyph. I can see why they like it, but it isn't for me. You could give it a try though.
Blood Strike--If you have some boss setup where a Warrior will be Thunder Clapping while you tank, this MAY be valid. Otherwise, look elsewhere. I would probably never use it.
The rotations I would use are:
AoE: IT>Pest>HB>BB>FS> Then, the rest of the battle will be: >BB>Oblit>HB>BB>FS>BB>BB>HB>BB>BB>FS, repeat. Your Oblit will give 2 Death Runes to BB with. Or, you can Oblit again. Your choice. Your HB will refresh FF, so you don't need to IT again.
ST: IT>PS>Oblit>BS>BS>FS>Oblit>Oblit>Oblit>FS, repeat.
Happy getting your *** pounded by Ulduaran evils.^^