This sweet Flash Datamapper application from the IMF allows you to look at world economic projections through 2013. The snapshot here shows the “current account” for each country, essentially exports minus imports. The timeline shows China continuing to soar and the US, after a dip, holding steady, still in negative territory. All of this data and much more is available for download from the IMF site here.
Update: 27/6/2018: Links still work, but Datamapper is no longer flash. Beautifully designed new (2017) interactive map!