Out of the box, a droplet should have 1 public IP address mapped to "eth0" and 1 private IP address mapped to "eth1" and both configure with Static DHCP for ultimate connivence. This way coping and moving droplets and starting them as a new servers would be very easy. If done so, that would satisfy the needs of 95% of the users. The other 5% have the technical means and resources to take care of their needs.
Linode has problems with eth1, so they ask people to create virtual interfaces eth0:0, eth0:1 for their additional IP addresses. With that setup, you must first mouth an backup on an existing node as a device, change your IP info, then unmount and deploy as a new server. That is not the right way of doing it.
Slicehost on the other hand, had this right from the get-go.
I am hoping that Digital Ocean follows the SliceHost Model and out of the box configures 1 public IP on eth0 and 1 private IP on eth1.