9/11 (however it happened) was used as a tool to freak us all out and put us into anxiety-rich paralysis. We tried to resist it for a few years and then EVERYONE shut down.
But Katrina is going to have the opposite effect. It will help us wake the fuck up. It shows EVERYBODY how crazy the Bush administration is, how ineffective they are, how the war in Iraq is really dangerous for our ability to care for ourselfs, how dependant we are on oil, etc...
This is threshold that we can use to revivalize and renew the culture of resistance and alternatives.