Read Expose actionkey's from plist is a code exchange entry by Qwerty Denzel that contains a routine to read out the system wide keys to invoke Expose (in its various flavors). For some reason, it does not seem to work with Leopard (dated july 2006).
Would anyone know how to update this matter…?

Hi Eelco,

in Leopard Exposé Preferences are scriptable e.g.

tell application "System Events"
	tell expose preferences
		get properties of all windows shortcut
	end tell
end tell