Changing NIC, but not IP

Howdy, I've seen some articles on AFP in the past that indicated that changing the IP of a OSX server could prove to be a hassle. With that in mind I'm doing a bit or research on what I might be facing if I change the NIC (increasing speed), but not the IP. Don't want to blow up my server, and not know what I've done. So IP and Subnet will stay the same, but MAC address/NIC will change. What should I be concerned about. ST