Channel 4 WWL
Two sites: WWL TV (New Orleans) was speculating it, and from the radar,it certainly looked like it to me, and people at http://www.easternuswx.com were saying it before I heard it at WWL. Water is pretty hot where it's going over temps in the upper 80s and 90s, and there have been some weather thingies going on a few hours earlier that may indicate strengthening like it did last night.
It's going to be a serious storm, whether it goes in at 150 kt, or 175kt,or 140 kt, but don't count on it weakening a lot before it goes in.
The latest storm discussion talks about this as well:
THERE HAVE BEEN SOME MODEST CHANGES IN THE STRUCTURE OF KATRINA OVER
THE LAST SEVERAL HOURS. RECENT MICROWAVE PASSES SHOW THAT AN OUTER
EYEWALL IS IN THE FORMATIVE STAGES...AND THE LATEST IR IMAGES SHOW
A LESS WELL-DEFINED EYEWALL WITH MORE EVIDENCE OF OUTER BANDING.
THE NOAA HURRICANE HUNTERS ALSO REPORTED AN EROSION OF THE EYEWALL
IN THE SOUTHWEST QUADRANT. THESE OBSERVATIONS SUGGEST THAT THERE
COULD BE SOME WEAKENING OF KATRINA PRIOR TO LANDFALL. ALL THIS IS
RELATIVE...HOWEVER...AND KATRINA IS STILL EXPECTED TO BE OF AT
LEAST CATEGORY FOUR INTENSITY WHEN IT REACHES THE COAST. AN EYEWALL
REPLACEMENT AT THIS POINT IS NOT ALL GOOD NEWS...AS THEY ARE
GENERALLY ACCOMPANIED BY A BROADENING OF THE WIND FIELD...SO THAT
EVEN AS KATRINA WEAKENS THERE COULD BE AN INCREASE IN THE AREA THAT
EXPERIENCES MAJOR HURRICANE FORCE WINDS.