Add this change to the login window defaults:
defaults write /Library/Preferences/com.apple.loginwindow AdminHostInfo DSStatus
Reboot, and you will get a red dot telling you when the network ds services is up.
You can try this to add a delay for the login window:
defaults write /Library/Preferences/com.apple.loginwindow StartupDelay -int 60
This 60 second delay will be stopped short if the network comes up before the 60 seconds is up,
and the login window app will display.
This and more can be found here:
http://quickies.seriot.ch/index.php?id=177