There was lots of buzz in Aspen, and I believe also in the press, about whether the "success" of the surge will or should cause Barack Obama to re-evaluate his stated Iraq policy. I think it's clear that if Obama does become president in January 2009, he won't and shouldn't super-literally apply a policy that will by then be almost two years old. But I don't think he should or will meaningfully alter his platform. It's worth recalling that all throughout 2007 it really seemed like Obama was going to lose the primary and that getting to Hillary Clinton's left by sketching out a clearer and more unambiguous withdrawal plan would have been a plausible gambit to beat her.
But he didn't do it because he wanted to preserve some flexibility in the event that he became president, and I have every expectation that he'll stick with that built-in flexibility during the campaign. After all, Obama's stated position on Iraq is fairly conservative. He's calling for the withdrawal of combat forces on a 16 month time frame. Realistically, that would mean the last combat forces leaving Iraq in June 2010 or maybe a little bit later depending on how long it would take between inauguration and actually setting the wheels in motion. Substantively, that's plenty of time to continue to try to have a constructive influence on the course of events there. And politically, if John McCain wants to make a big deal about how two more years of war isn't long enough, then he's going to lose badly.
On top of all that, Obama has always had a pretty vague formulation about residual troops and liberals, myself included, have always criticized him for that. I don't think that's the correct policy, but it's one Obama's long maintained and it means he's always had a "centrist" Iraq position rather than a "bring the troops home" position.