The colocation facility where Westeros.org is hosted was compromised by some crackers installing rootkits. Sparks has taken some of the server functions down, and that seems to cover HTTP or the server where the forum and wiki are right now. Westeros.org sites such as the Citadel, All Sorts of Weird Stuff, Game of Thrones, and so on are currently working, as is the Blood of Dragons MUSH, however.
Will update when we’ve more information.