I once had a server (in the pre-udev era) that would occasionally shuffle its network devices after reboots. I don't remember how I fixed it but I do remember the short phase of amusement, followed by a longer phase of frustration.
Moving a PCI card to another slot should also not rename the device. With a typical current udev setup, device names are persistent based on MAC address. With this proposal, either the name will change if the bus topology changes, or bus location based names will be _wrong_. As usual the fedora/desktop trolls are breaking perfectly good things for no apparent reason at all.
But otherwise I understand that devices are detected in parallel and whichever ones return first are designated eth0, eth1 etc.
We had this problem on some machine that have 4+ eth0 devices. We use RHEL|CentOS 5.x (see in the post above how we solved the problem).