The Moorsetown chips are basically Intel Atoms built on a smaller die and clocked from 1.2GHz to 1.5GHz, while maintaining a lower battery consumption.

Medfield is the successor (to Moorsetown) and they're supposed to try to improve battery consumption and/or improve performance. They can clock above 1.5GHz (perhaps even to 2.0GHz!).

You do know Intel said no Medfield devices (I believe until 2012). It is the Moorsetown platform that will be produced and sold in 2011. Also Nokia said the N900 successor/first MeeGo phone/N9 will ship in 2011. Thank you, my logic is amazing