I'm testing the Atlanta release and my interfaces are not being ordered properly.
I have two onboad, and an Intel PT1000 dual port and a Supermicro Dual Port IGB based card.
Usually, you'd expect the onboard NICS to be eth0 and 1, but in this case, one of the onboard nics is eth0 and one is eth3. I think as a part of the setup, you should be able to configure what card is what based on mac address. Debian is notorious at reordering your NICS whenever it wants to....