Hello!
Seeing how there is cold/vitality/aether damage both in current itemization and in the upcoming Necromancer mastery, I could very well see a caster wearing Bands of the Eternal Haunt and spamming Haunt all over the place. It kind of works already, but being able to spam it and scale it with %casting speed would be awesome.
Couple that with Bone Harvest and Spectral Binding and you get a pretty sweet mage build.