As of Perceus 1.4 nodes will no longer automatically get an ip via DHCP. You must first enable and configure the ipaddr module in Perceus.
perceus module activate ipaddr
Then, edit the ipaddr config file in /etc/perceus/modules/ipaddr. Uncommenting the last line seems to be more than sufficient for most configurations. If your machines do not have their second ethernet card plugged in it is worth removing the eth1 portion as this will significantly reduce boot times.
* eth0:[default]/[default] eth1:[default]/[default]/[default]
Reload the Perceus service, and then restart the nodes and they should automatically get a new ipaddress.