I'm not a big fan of Bush, but I won't bash him for his response to Katrina.
The man handles big situations likes this very well. I seriously think he's doing his best.
Honestly, I don't think any of us have the right to say what he should or shouldn't do. He has a lot of pressure on him, and people trying to tell him how to do his job doesn't help any. I say people get off his back, and let him do what he can. There's only so much he CAN do. He's not God, he's a human. His power is limited.