The story of 2011? The crisis in the Euro.
Of all the events of the year, this is the story that carries the most direct danger or hope to the most people. If regarded as a single economy, the Eurozone is larger even than the economy of the United States. If the Eurozone cracks apart --if southern European countries begin defaulting on their Euro-denominated debt--we'd see a financial crisis and recession in Europe. That crisis and recession would surely spread to the rest of the world, including Canada and the United States.
If on the other hand the Euro is rescued through meaningful reforms, we can hope for more growth in Europe--and a more positive outlook for North America. Everything is at stake. The fate of the world economy, and very likely the outcome of the U.S. election, now depends on decisions made across the Atlantic. Which means the biggest story of 2011 will likely expand into an even bigger story in 2012.