Currently, AFAIK the 'script' media type does not pass along the priority of the trigger beeing activated to the script. This can be very handy for scripts that interface to Prowl or NotifyMyAndroid for example, where you can set quiet hours for non-emergency alerts for example. That way i can get the critical errors 24/7, and only get high ones during the day. I can also assign different ringtones to the various priorities as well.