So, I have been thinking about this lately, and I have come to an odd conclusion...
But, first, my logic:
If there aren't multiple targets, than Pestilence and DnD are useless. To be fair, I don't know if, in general, boss fights in Wrath are AoE based, so... this is just theory.
Other abilities that use blood runes (and aren't talents):
Blood Boil... useless in normal situations, let alone in a boss fight.
Strangulate... I don't know the resist rate on this ability, but I can see it being useful if it lands frequently.
<insert ability I possibly forgot>
Now, to get the maximum affect from Blade Barrier, I need my runes on cooldown as often as possible. So I cannot really be waiting around just for the chance to use Strangulate...
So, should I just be using Blood Strikes to convert the runes to Death Runes? Or is there something I am missing?
Now, if most bosses ARE AoE fights, than this whole thing is more or less moot...