Its one of those minis that initially looks quite familiar (ie like a reworking) but when you take a close look, it is quite different. Comparing the pics, even the flames on the back of the disc look different.
I really like the sculpt of the head, the robes and the staff. The inscription on the disc is cool too. Not so convinced on the tentacle/flame part where the sorcerors legs should be, or the hand holding the staff, but thats all easily fixed.
Of course, it helps that I play Tzeentch for both 40k and Warhammer. Hope it makes its way over here at some point. GW Spec Ed models have a habit of cropping up at other special events now and again