Hillary in 2012?

I admit I voted for Hillary in the primaries. I think that she is the best candidate overall to make the changes we need in Washington. But I'm coming to terms with the very real possibility that Obama will take the Democratic nomination. So I ask myself, with the race going this way, why is Hillary staying? Is she staying so that a dialog will remain open in the Democratic party? Is she hoping that some miracle will happen and all the super delegates will swing her way? (Which, by the way, I'm praying for!) Or is she laying the groundwork for her next run in 2012?