RapidScat (a new Earth observation platform on the International Space Station that re-uses materials designed for QuikScat);
Curiosity Mars rover's MastCam (which is based on a successful design used in the Spirit and Opportunity rovers). The earlier version of MastCam has been working on Opportunity since the rover landed on Mars in January 2004.
Venus Express, a European Space Agency mission that uses designs and hardware from the Mars Express and Rosetta missions. It's finishing its mission soon after eight years in orbit -- four times the original plan.