Originally Posted by DarthJacen
Again, since the mod is client-side only and aesthetic at that, it doesn't break EULA. Look at the web site dedicated to MMO modding call ModSource.
It depends on what they put into the EULA, in WoW you only allowed to use the facilities Blizzard providing, meaning that you could not change textures or models. They never actually stopped anyone who did, IIRC, but that was still in the EULA.