Intrade is apparently starting to include contracts on the future of aggregate economic measures (e.g. GDP growth rate or unemployment rate changes) conditional on political outcomes (e.g. Hillary gets elected) at the suggestion of a research initiative of the Westminster Business School; such conditional prediction market contracts are central to Futarchy. Now, perhaps, we will be able to see if prediction markets can make good predictions about these topics, though they may be too thin to reveal much information.
Looking at the contract prices and volumes on Intrade (Markets->Politics->Impact of Next Pres.) right now, the markets look pretty thin, but perhaps eventually they will have significant impacts on elections.