Paris Hilton's response to McCain's ad has already caused such a stir that McCain's camp has had to issue a response of its own.  As documented at Open Left:

Due to the extraordinary number of inquiries, please see our campaign's response to Paris Hilton's recently released video in which she puts forward her version of an energy plan:

"It sounds like Paris Hilton supports John McCain's 'all of the above' approach to America's energy crisis - including both alternatives and drilling.  Paris Hilton might not be as big a celebrity as Barack Obama, but she obviously has a better energy plan." ---Tucker Bounds, spokesman John McCain 2008

http://www.openleft.com/showDiary.do?dia ryId=7347

Matt Stoller and Chris Bowers both view this as a huge problem for McCain because now his clever little attack ad has caused him to get into a public and ongoing spat with Paris Hilton, of all people.  His campaign has devolved into an Extra! featurette.