I went with something similar, with a slight respec this morning - but I considered both points in Decimate necessary, for the cooldown reduction on Smash. With the acc debuff, I want it available as much as possible. I hold back sometimes so I can pop it right before specific boss abilities or phases, but the 3 second difference is nice.
What floors me, is last night in Lost Island (both normal and hard modes on LR-5), our Marauder who respecced from Annihilation pre-1.2 to Carnage now in 1.2, seems to be pulling aggro like CRAZY.