Just found this.
Get into card view or the launcher.
Type: upupdowndownleftrightleftrightbastart
You'll see this: Developer Mode Enabler
I don't know what precisely this is or what it does.

EDIT: opens up a Developer Mode switch:
"Turn Developer mode on to turn on Developer Services on the device."
You will need to reboot the Pre to effect your changes.

After having rebooted, I don't see anything obvious.

Found via:
webos/resources/webOS.tar =>
nova-cust-image-castle.rootfs.tar.gz =>
usr/lib/luna/system/luna-applauncher/app/controllers/global-search-assistant.js