In case anyone's wondering why their shader doesn't look exactly the same: he's got a subdivision surface applied to the mesh with Render at lvl 5! Tell the people!
This will be a lot easier when Cycles new microdisplacement tool is integrated into a release build, some of the examples taken from the following thread are incredible - http://blenderartists.org/forum/showthread.php?396697-Cycles-new-microdisplacement-build-and-testing
