Except that it won't be as strong a storm as Katrina.
How do you know this?
That's true, it's not forecast to strengthen as much as Katrina (I wouldn't be surprised if it does though, as hot as the Gulf water is right now - it all depends on wind shear). There was an implicit 'all else being equal' in my previous comment. However, bear in mind that Katrina was 'only' a Cat 3 by the time it made it up around NO and the Mississippi coast. Rita is forecast to be a Cat 3 at landfall.