From My Modern Met:

Yesterday morning, March 5 at dawn, National Geographic Channel and a team of scientists, engineers, and two world-class balloon pilots successfully launched a 16' X 16' house 18' tall with 300 8' colored weather balloons from a private airfield east of Los Angeles, and set a new world record for the largest balloon cluster flight ever attempted. The entire experimental aircraft was more than 10 stories high, reached an altitude of over 10,000 feet, and flew for approximately one hour.

I would have expected something like recreating the house from Up to be a segment on Mythbusters but it's not. It's for a new show on National Geographic called How Hard Can it Be?.

More photos.