The campaign just released this statement:

“John McCain has built a solid grassroots organization in Iowa and intends to win the state’s caucuses. He appreciates the unique and critical role the caucuses play in the nomination process and enjoys traveling the state, meeting Iowans, and holding town hall meetings.

“In light of today’s news, it is clear that the Ames Straw Poll will not be a meaningful test of the leading candidates’ organizational abilities, so we have decided to forego our participation in the event.”

Clearly, he’s using Rudy’s decision as a cover to bail out of Ames. It’s also uncertain whether Fred Thompson will compete. If Thompson skips too, then three of the frontrunners will not be participating, removing a lot of the significance of the event. The question now is how much Romney will benefit from his near certain victory in Ames.