Okay, I did a little research, because it is very relevant.

Obama's position, one can assume, should match the bill he sponsored in the Senate. In particular, it requires that benchmarks for progress be set that are prerequisites for removing troops, enhancing training of internal forces, increasing diplomacy, etc. It should also be noted that he was always against the war, speaking against it publicly before it started.

Hillary Clinton has really always been pro-war, and it's only lessened today due to public pressure. That said, she also is in favor of a slow withdrawal, albeit her position changes so often it's hard to nail down exactly what she wants to do.

Edwards voted to approve military force in Iraq but has since apologized for that vote. He also is interested in a slowish withdrawal, speaking specifically of replacing American contractors with Iraqis, but has also spoken of having all troops removed within ten months of his election.

Recently, all three Democratic candidates have stated that they expect that the US will have a presence in Iraq for at least another four years.

Ron Paul was initially opposed to the war, and continues to be. Like Obama, he introduced a bill intended to remove troops from Iraq. His was intended to remove authorization for the use of military force with Iraq in six months time. His position would seem to be the most radical of the major candidates. He claims that it does not set a timetable for removal from Iraq, but I fail to see how removing authorization for military force would not result in a removal of military force.

All of the rest of the Republicans are pro-war, so we'll not see any sort of impetus to remove the US from Iraq at all.