1. Exposure: He received free uninterrupted TV time. He didn't have to share the state with Duncan Hunter or Tom Tancredo, either. At the very least, everyone is talking about him today, and it cost him nothing.
2. Image: The image of Mitt Romney standing next to George H.W. Bush probably won't hurt him in a Republican Primary. He looked presidential.
3. Putting it Behind Him: In the future, whenever he is asked about the Mormon issue, Romney can always say: "Look, I'm not going to comment because this is old news. I gave an entire speech on this ..."