No, not yet. I really hope it would be soon since they did the same thing with the Ninja Lore Pack spells, and considering the theme of the spells, it would be logical to assume that whatever boss that drops the Deer Knight (and the Handsome Formori and Catalan spells too) would be somewhere in Avalon.
I really want to farm bosses for the Death and Ice spell for my respective wizards and my brother wants the Storm spell! :D
As a death, i can truly say: I could easily make this spell do 1,000 damage on the second round of battle to all enemies and then trigger a do over time. In other words, I want it and I hope it is dropped.