Barcepundit is correct that Bush didn't say he would invade even if Saddam complied. But even if it had said that, that's not really the most damning point. Consider Bush's statement:
"If we act militarily, we'll do with great precision and focalizing our targets to the biggest degree possible. We'll decimate the loyal troops and the regular army will quickly know what it's all about. ... We are developing a very strong aid package. We can win without destruction. We are working already in the post-Saddam Iraq, and I think there's a basis for a better future. Iraq has a good bureaucracy and a relatively strong civil society. It could be organized as a federation."
Up until "We are developing a very strong aid package," his predictions proved correct. He was also correct that U.S. forces would not need to destroy very much. However insurgents/looters *did* destroy quite a bit (not just the museums and libraries but also the power and water infrastructure). He was absolutely wrong about Iraq's bureacracy and civil society. And so far Iraq has not been able to organize as a federation.
To me the most damning statement of all is "We are working already in the post-Saddam Iraq." This seems to say that the U.S. is already preparing (if not prepared) to occupy Iraq. At the very least it suggests that the post-invasion planning is in place. It may be true that he thought the planning had been completed, but we now know that U.S. forces were entirely unprepared for the unrest and insurgency that followed 2003.
More: This Bush quote from a press conference with Amb. Crocker underlines the point...
I heard somebody say, Where's Mandela?' Well, Mandela's dead becauseContrast with "Iraq has a...relatively strong civil society." killed all the Mandelas.