I know it may be a little soon to be calling for new elites in future expansion but I have to say it! I would love a well elite for the necromancer. Right now I run a well heavy build for dungeons and my elite bar has always felt empty. The forms are decent for certain situations but I feel like spending time in them takes away from other things I could be doing with my death shroud and marks. An elite well would be perfect for providing AoE conditions with the ability to keep with the flow of battle.
As far as an Idea of what it could do, I think life stealing for you and your allies would be ideal!