A hurricane this size will continually go through the eyewall rebuilding cycle. This is what can give the hurricane a "wobble" and also causes the intensity to fluctuate. It actually has had 2 eyewalls as an outer wall decayed while a new inner wall grew.
Here is a real sexy computer model of Frances:
http://www.noaanews.noaa.gov/stories2004/images/frances090104-1215zb.jpg
Prayers up!...for my family and others in the potential path.