Just a note that my wifi card (broadcom 1397) could not connect to non-WEP encrypted networks (WPA, WPA2 etc) after 10.8.4, but restoring airportd from 10.8.3 as suggested in another thread appears to have worked
re-attached that file here
replace the /user/libexec/airportd with this one, fix permissions to 755 & root:wheel ownership. I also removed the apple quarrantine flag:
xattr -d com.apple.quarantine /user/libexec/airportd