Again, as if we need more proof, we find that the intel on WMD wasn't as strong as believed. News? No.
I think after a while we have to ask the question, "How solid does your information have to be to go to war?" There are several angles to take here, of course, ranging from absolute proof (which may come too late, see Iran) to if you have suspicion (which may blow up in your face, see Iraq). After we get through asking that question, I'd ask, "Was the information Bush and co had up to any standard of proof?"
At the very least, for every yes story there was a no story. Some of the sources for the yes stories should have been deemed non-credible from the start - Curveball. Perhaps, as is argued in the comments in the link above, some of the sources for the no angle could be discounted for suspicions of subterfuge. Possible.
But when you shake all of that out, was the information we had credible enough to take us to war, or was there an agenda there that made information at best a helpful tool?