No. It's a prediction about what would happen if something else happens two years in the future. After two more years of Obama revealing his ineptitude and Palin defying her detractor's predictions of doom, you just don't really know, do you?
The reality is not that Sarah would lose. The reality is that she is the one person other than George W Bush who the Left will excoriate so badly that, to the independents, all the negativity around Obama will seem to fall by the wayside. If you don’t understand that then you don’t understand how independents think.