With udev on debian, you can specify the eth0 eth1 ethN interfaces by using /etc/udev/rules.d/70-persistent-net.rules (or whatever rule file that your distro uses) to fix an IP address to a specific MAC address and interface.

No longer do you have to use modprobe.conf or modprobe magic that kind of worked (plug everything in, config it, and hope the boot order won't change ;) back before udev. Hurray for progress! ;)