I like it too. And I think its a release in the same spirit as the Chaos/ Dark Elf ones. A way for GW to introduce new model that benefits the players in the Storm AND ordinary gameplay..
However, its an awsome model that i perhaps gonna buy. Thing is, if you get a second rider (you get 2 to the Chaos one) then he can act as a mounted vampire in my Mordheim band. (just gonna get a campaign going, and survive long enough to get the mounted skill....)