Ambinder has a 2004 clip of Obama resisting "an artificial deadline" for withdrawal from Iraq, and talking about "rebuildin" Iraq properly. Republicans may look to make hay of Obama's change in position, but this is hardly news--Hillary was making the same critique during the primaries. My sense is that voters--and, yes, pundits--are mainly interested in Obama's initial opposition to the war and his current pro-withdrawal position (however nuanced), and not all that interested in his meanderings along the way.
An interesting counterfactual question is whether Obama would be in the same position today if he'd called for withdrawal back in 2004. It was a pretty taboo position at the time and he would have taken tremendous heat for it.