Second quick video:
YouTube - Blink Notifications in webOS 1.2
Shows the center button lighting up for notifications (and yes, I know the focus is horrible but I'm not going to redo it).
There's a few lines you need to comment out to get this to work:
In /usr/palm/applications/com.palm.app.screenlock/app/controllers/securityconfig-assistant.
js:
Uncomment lines 54,55, and 248-251.
In /usr/palm/applications/com.palm.app.screenlock/app/views/securityconfig/securityconfig-scene.html:
Uncomment 92-97 and 101-103.