I used the same SD card I had used in one of my Raspberry pis in a different Raspberry Pi board, and after rebooting it did not show up on the network.
Hooking up an HDMI cable an monitor showed that "eth0" device was not found.
It turned out that a rules file is generated based on the MAC address, and since this board had a different MAC address it created a new rules entry for eth1 for this MAC address.
Solution is to edit the file: /etc/udev/rules.d/70-persistent-net.rules and assicoate the new MAC address with eth0.
See here: http://www.raspberrypi.org/forums/viewtopic.php?f=28&t=90319
