its very interesting that the NYT has this headline, but as far as I can see, does not report on Bush's acual mea culpa. what gives??

the actual words are reported elswhere.
Bush Takes Responsibility for Failures in Storm Response - New York Times: "Bush Takes Responsibility for Failures in Storm Response"
the washington post is till reporting that bush is defending the federal response
45 Bodies Found In La. Hospital
Bush Visits New Orleans and Defends Federal Response; FEMA Chief Quits

Meanshile, this is on Reuters:

WASHINGTON (Reuters) - President George W. Bush took responsibility on Tuesday for failures in the federal government's response to Hurricane Katrina.
"Katrina exposed serious problems in our response capability at all levels of government, and to the extent that the federal government didn't fully do it's job right, I take responsibility," Bush said. "I want to know what went right and what went wrong."
The Boston Globe actually lets Bush say he takes responsibility:
President Bush said Tuesday that "I take responsibility" for failures in dealing with Hurricane Katrina and said the disaster raised broader questions about the government's ability to respond to natural disasters as well as terror attacks.
"Katrina exposed serious problems in our response capability at all levels of government," Bush said at joint White House news conference with the president of Iraq.

"To the extent the federal government didn't fully do its job right, I take responsibility," Bush said.

even the Houston chronicle lets bush assume responsibility:
Bush: 'I take responsibility'
President says disaster has exposed serious problems with ability of government to respond