This is only what I've heard on our local news, but they seem to be valid reasons: 1) the HP system in the GoM is expected to move westward in a couple of days. I believe this feature is what is (for now) keeping Wilma from moving anywhere. Once this system retreats westward, it will allow Wilma to move in a general northerly direction.
2) There is a cold front coming down from the Plains that could pick up Wilma once she starts moving more northward and depending on where Wilma is and when it picks it up, will probably be where Wilma eventually ends up.
The "where" cannot be answered right now, though. I would say that everyone from Florida to N.O. needs to be paying attention to this storm. I do know that our local weather stations are a bit more concerned with this storm *at this time* based on these two weather features.
Hope that helps and hope that I explained things correctly! If not, anyone can feel free to correct my post!