Robert Gibbs gave a preview at the WH Briefing...

This is an important step forward in this process. We are handing responsibility to the Iraqis for an increased level of security situation as well as responsibility that comes with needing to work on and resolve their political reconciliation.

The President will talk about why it's an important step but why we have to remain vigilant in monitoring the situation.

He will discuss the reason we're at this point: The courageous contributions of our men and women in uniform.