They did put up a download post on another site, called minecraftsandbox.com Its a few pages back. I downloaded it, but its hard to explore the castle in single player. Way to many monsters. I have been meaning to install it on my server, but haven't gotten around to it yet.
EDIT URL
LINK???? im thinking about building one but i need alot of screenshots and stuff
http://www.planetminecraft.com/texture_pack/heartscraft/
I want to use this in my SMP server - where / how do I download?
(I should really feel ashamed by how happy this has made me.)
http://minecraftsandbox.com/2011/07/harry-potter-hogwarts-castle-done-up-minecraft-style/
Could I use this map on a server? As long as I give you credit?