Brown out, but not fired (yet)
Brown is no longer in charge of dealing with Katrina, but he isn't actually fired. Translation: they're trying to thread the needle. They don't want the humiliation of a firing but they want Brownie out of there as quickly as possible so as to stem the embarassment.
Potential Talking Point: The emergency is over, the recovery is beginning, thus the Federal Emergency Management Agency head is no longer the go to guy. Thanks for your great work Brownie!