As you will already know by now The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel 2009 has gone to Elinor Ostrom and Oliver Williamson for their analysis of economic governance. Eric discusses the prize here and here, while Brad Taylor comments here and here. They mainly discuss Ostrom's work since no one would have picked her. In fact most economists couldn't tell you much about her work at all. I will post on Williamsons' work when I have a spare few minutes since I know more about that.