Read the Original Article at http://www.informationweek.com/news/showArticle.jhtml?articleID=240049888
The voting application runs in a Microsoft Azure cloud. The application prints the completed ballot on a separate printer and the voter approves and submits that ballot.
The test is being run by Democracy Live, an electronic voting software and services company. According to Geekwire they have more extensive plans for Surface when the Intel-based Surface with Windows 8 Pro is available.
Hat tip to CNet.