For months--exactly a year, actually, since Bush/Cheney's "re-election"--I've been carrying a sign demanding their impeachment for having "lied U.S. to war," and our little band of weekly protesters has been chanting to the same effect. It's satisfying to have history catch up with us a little, I must admit, although 1000 U.S. troops have died in the process; but I'm not certain how penetrating any Congressional report on the subject of the Bush administration's fabrication of evidence will be. The Republicans control that process, so I'm not holding my breath.
I will point out, however, that a new storm cloud is rising on this score. Compare this item, appearing in 2004, but citing evidence dating back to many months before the war, with the NYT article today that cites a report by the Defense Intelligence Agency about the lack of credibility of one of the sources for Bush's claims of a connection between Saddam Hussein and al Qaeda.
Result: A main source of Bush/Cheney's claims (as well as Colin Powell's speech to the U.N. Security Council) about Iraq's threat were made up by a stoolie who was out to please his captors--and the DIA reported this fact months before the invasion.
So--We'll keep chanting, and I'll keep on carrying my sign.