I don't really buy into the liberal talking points that the Bush administration lied or was misleading about Saddam's weapons of mass destruction before the invasion. There was considerable evidence (although most of it was circumstantial) at the time that Saddam was hiding a weapons program. But I think it is becoming more apparent that they were purposefully deceptive after the invasion.
The so-called mobile labs that Colin Powell talked about in front of the UN before going to Iraq, were found soon after the invasion. This Washington Post article suggests that when these mobile labs were found, President Bush, despite contrary evidence from the field, said that they presented proof that Saddam had a biological weapons program (the administration is disputing the timing).
I usually watch the news during my lunch break, and I have had the fortune of watching the White House Press Briefings - also known as the Daily Beat-downs on Scott McClellan. As stories like the Vice President's hunting accident, the CIA leak investigation, and the mobile weapons labs reach the press, the press take out their anger with the administration on McClellan. While the administration might not be lying, they obviously don't care enough about the truth to wait for it to come out. Instead, they report whatever might sound good long before it can be confirmed - or denied (Harry Frankfurt calls this bullshitting). Whatever it is, bullshitting or lying, this administration keeps getting caught and it is really hurting their public support.