devices, services, thresholds, and ART checks could have a field where you set a default priority. When an incident opens, the 'priority' field is set to this default. If left blank, so it priority, which allows seamless migration for old customers.
If device has a priority but service/thresh does not, set incident to device priority.
Then you could 1) add priority to key displays, like incident list and NOC view; 2) sort incidents by priority ; 3) add priority as a function in incident management rules, so you could take different actions based on priority.
This would add tremendous value to large customers, and has been a common request.