Enabling biosdevname (described at http://linux.dell.com/files/whitepapers/consistent_network_device_naming_in_linux.pdf) is an option for Ubuntu and has been since 11.04. It is not yet enabled by default, but it is an option that can be enabled by passing the "biosdevname=1" option at boot. I am not sure if it is desired to allow this feature in live images (such as the Ubuntu Cloud live image), but, if it is, it seems like there may be a couple of bugs one may encounter when doing so because of a couple files in the casper package:
dell@dhcp-164-224:~/precise/casper-1.312$ egrep -r "eth" * | egrep -vi "([a-z]eth|eth[a-z]|^test|^doc|^po|^man)"
debian/changelog: * Write /etc/network/interfaces entries for eth0, eth1, eth2, ath0 and
scripts/casper-bottom/23networking: for interface in /sys/class/net/eth* /sys/class/net/ath* /sys/class/net/wlan*; do
scripts/casper-bottom/23networking: for i in eth0 eth1 eth2 ath0 wlan0; do
scripts/casper-bottom/24preseed: chroot /root dhclient eth0 3>&- 4<&-
scripts/casper-bottom/24preseed: chroot /root ifconfig eth0 down
I am not familiar with how casper functions, so I'm not sure if this would be a bug or if these files in scripts/casper-bottom are harmless. I will note that on an Ubuntu Cloud live image that I tried, passing "biosdevname=1" did not do anything, so it may be that this is not possible for that build anyway.