There's no link for this one; it's in Novak's political report. Novak echoes a point I have made here recently:
Although President George W. Bush officially is opposed to setting any time table for getting out of Iraq, senior administration officials and Republican leaders in Congress privately say there cannot be U.S. boots on the ground or blood being spilled in Iraq when 2008 begins if Republicans are to have a chance in next year's elections. That effectively sets a December 2007 deadline for getting out.
I think there might be a few more months, but for better or worse, I think this is largely correct.
If the surge goes well, I think the best that can be hoped for - in terms of popular perception of the war - is that it's OK for American troops to continue in Iraq in a role that generally keeps them out of harm's way. The Democrats and the media have too much invested in the failure of the US effort there to allow it to be perceived as a victory. So if things improve, the goalposts will be moved.
Either way, the role of US troops in combat in Iraq will be over early next year.