Was previously using nvram -p to check the security-mode, since this doesn't work with the late 2010 hardware onwards.. Here is a short extension attribute that will tell you whether the password is set, though unfortunately not the mode.
If anyone knows how to determine the mode.. please share! It's not an option in the setregproptool.
#!/bin/sh
EFIP=`/Library/Application Support/JAMF/bin/setregproptool -c; echo $?`
echo "EFI is $EFIP"
echo "<result>$EFIP</result>"