Cute model. The staff looks fantastic, and from the previews I would disagree with other posters about it being too big. Although, I haven't seen it in-game compared to other units, so I can't be sure about that.
The biggest issue here is that most of the model (the body, robes, etc) are identical to the Orc Necrolyte. At the very least, the texture should be played around with and changed. I would love to see some other changes, though - a big, gory necklace with animal \ humanoid bits, a belt or trophy sack to replace the Necrolyte's book and loincloth, maybe some different, furry boots. Swapping out the hood and shoulder-poncho for something else would do the trick just as well.