From AP:

President Bush and his vice president conceded Thursday in the clearest terms yet that Saddam Hussein had no weapons of mass destruction, even as they tried to shift the Iraq war debate to a new issue—whether the invasion was justified because Saddam was abusing a U.N. oil-for-food program.
...
Bush and Cheney acknowledged more definitively than before that Saddam did not have the banned weapons that both men had asserted he did — and had cited as the major justification before attacking Iraq in March 2003.

Bush has recently left the question open. For example, when asked in June whether he thought such weapons had existed in Iraq, Bush said he would "wait until Charlie (Duelfer) gets back with the final report."

In July, Bush said, "We have not found stockpiles of weapons of mass destruction," a sentence construction that kept alive the possibility the weapons might yet be discovered.

On Thursday, the president used the clearest language to date nailing the question shut:

"Iraq did not have the weapons that our intelligence believed were there," Bush said. His words placed the blame on U.S. intelligence agencies.

So now finally Bush has admitted that there were no WMDs in in Iraq. I just reread that ultimatum, and rationale for the war, condensed, is as follows (full text here):

The UN passed resolutions requiring Saddam to disarm with penalty of military force. He has disregarded those resolutions by not complying with inspectors, and also because we have intelligence which says he actually has WMDs. Terrorists could potentially use these WMDs without warning. The longer we wait, the bigger this threat becomes. Before terrorists have a chance to get WMDs from Saddam, he must be disarmed. Some countries have decided to not yet act with force. We disagree, so we are going to use force.

That's the reason he gave in his speech, and that's the reason he was giving to the UN prior to giving that speech. Now, even as he admits that reason was totally incorrect, he is still defending the war. That's totally unacceptable.

Regardless of any benefits of getting rid of Saddam, those do not justify going in and doing it at the wrong time, for the wrong reason, and without the support of any sort of formal treaty organization.

That is all.