Does this even work on the wireless interface on a mbp? The driver used to prevent you from setting the MAC addr to anything you wanted, vs the ethernet driver for the wired interface that lets you play with it freely.
In my experience, my macbook pro MAC address can be changed with the bash command listed in the file for wifi (sudo ifconfig en1 ether [addr]), but it will not let me change it to any arbitrary address I want, just some of them, including addresses that start with aa:[rest], ab:[rest], etc., which is what I usually go for. Just tested it and en0 doesn't seem to have the same limitations.