Erm, if you're low health, how would you not have taken damage recently? Unless your healer was either dead, afk, or drooling on his keyboard from having fallen asleep. (In which case your death would not have been your fault, it would have legitimately been the healer's fault.)

it really jsut depends on what you're tanking, but you can use the blood runes for runetap or convert one to a death rune for bone shield or DnD so dont lose a death strike. In aoe stutations you can spread diseases with pestilence, cleave with heart strike, or aoe with bloodboil. While the threat might not be needed anymore, you might as well dps while your death runes cooldown. Then again you might be better off ignoring the blood runes completely when you can so you can refresh more death runes with rune strike. Maybe they'll eventually add something more compelling to do with blood runes, so it won't feel like a penalty when they get refreshed by rune strike. Perhaps (as poster below suggested) they could disconnect the shield from the heal--maybe attach the shield to heart strike and leave the heal on death strike. Then you could also choose which to spend your death runes on.

I think Death Knight tanks needed a couple fewer balls in the air, but my immediate reaction is that the changes GC outlined are taking it a bit too far. Hopefully they don't go the route of greater resource management with the other tanks. I think that's part of the problem with DK tanking (although a lot of that will go away once you don't have to maintain blood barrier).