The local preparation and response, which in every natural disaster constitutes the bulk of the immediate response effort until the feds can put significant assistance assets on the ground, was woefully inadequate.
The feds proceeded as they always do, but the local response collapsed before it started under the crushing magnitude of need and crippled infrastructure, creating a much greater lag time before any help arrived, making it seem like the feds were sitting on their hands, when in fact we may find it surpassed every other previous federal response.
An analogy would be if someone were breaking into your home, you called 911, but the local police were absolutely overwhelmed, so you had to wait for state police to respond from the nearest post much further away. Happens all the time. The state police response may be as good as it gets, but if you have to wait what seems like a tortuously long time in fear or despair, you're going to be pissed-off at whom ever gets to you first, as though the lapse was on the part of the state police and not the local police.
I see at least one reporter is trying to undo some of the massively lop-sided media coverage that New Orleans received that grossly distorted the public's perception of the National Guard's burden:
Mississippians' Suffering Overshadowed
Now if we could just get a hundred more articles and television reports of the total devastation between NOLA and Biloxi, it might counter the perception that only New Orleans was affected or in dire straights.
Had I been watching the media coverage, totally unaware that pretty much everything between NOLA and Biloxi is leveled or under water as far as 20 miles inland, thousands of OTHER people needing help who apparently have few friends in the media, I might conclude that someone bungled the response badly. After all, only New Orleans is in urgent need of assistance, what is the holdup? Its just one city, what could all those rescue teams and National Guard troops possibly be doing?