Hello Greg,
Thank you for asking about the EMAC code. Here a brief dossier about its status:
EMAC demo sample code is running OK using Arduino IDE 1.5.2 and a third-party Due-based board, enabling it to respond to a ping command sent by a computer. See reply #67:
http://forum.arduino.cc/index.php?PHPSESSID=5i6p7elee9gv585u7626tb7mn7&topic=142908.60
So far, I have a ported EMAC library (from AS6 ASF) with the Media Independent Interface (mii), mini IP structure (mini_ip) and the phy driver (conf_eth) files. I also had to modify the emac files (.c, .h) that you mentioned, and the variant files (.c, .h) from the IDE152. Notice that IDEs 1.53 and 1.54 do not have the emac pin definition/configuration. The next step is to create the EMAC class and overload some functions under the Arduino style. Regards!