Yes very useful reference, the syslogd.plist edit for permanent logging completes the story nicely.
See also Apple Tech Article ID: 107993
Link:
http://docs.info.apple.com/article.html?artnum=107993
AirPort Extreme: Remotely logging base station activity with syslog.
It is a useful example covering other generally relevant points.
But just uses terminal shell command to open the syslog udp 514 logging port.
It worked for my Airport Express Base station logging via WIFI.
Points to note-
1. MacOSX Sharing firewall.
syslogd UDP port 514 must be open for these messages.
(If the firewall Advanced option UDP Blocking is enabled )
2. /etc/syslog.conf:
A separate log file is created, but local0.* is used by the MacOSX firewall and the Airport Express and probably other devices, so you get firewall and other logging in both the ipfw.log and the AirPort.log. (grep could help here).
G5PMac,G4iBook Mac OS X (10.4.2)