Even some of the pro-abortion ones are willing to switch. They were going to do it just to vote against Obama, who they rightly see as incompetent, but Palin is just icing on the cake. They believe that McCain/Palin will win now and will leave the door open for Hillary in 2012.
I don't have the heart to tell them I'm one of Hillary's 18 million voters and that it won't happen again. =)