Don't bother with UH DK's AoE, it's already tremendous as it is currently, specially if you talent that fire chain with your pet (that, alone, is one of the best AoE damagers in the game, lasts a 'long time', it's only 'flaw' being that you have to keep repositioning yourself in a way that the line hits the most targets).
I really wish 2H Obliterate was getting some love ...
PLEASE BUFF UNHOLY DKS ON ALL FRONTS!