I think the Loews chain allows them. If I'm not mistaken that includes the Portofino at Universal. Probably have to be crated though. Here's a link http://hotels.about.com/od/orlandopets/ it lists all of the onsite Universal hotels!
from the Kissimmee visitor bureau you can get a list of the houses (yes, I say houses - houses are very reasonable in the area), condo, townhouses and hotels in the area that allow pets.
Kissimee is the next town over from WDW. (Orlando is further away)