When you click on the magnifying glass next to the owner and then click on the blank area next to the owner name on the Incident form, all the queue members show up but don't display in alphabetical order and can't be sorted.
1) Create multiple Queues and add multiple Queue members to the Queues.
2) Add the StaffAssignmentPage Visualforce page to Incident form layout.
3) Open an existing Incident from either Incident or Incident Console.
4) Click on the Queue lookup and click on the blank area next to the queue name to view the members.
The members should show up alphabetically by the Last Name as they do when clicking on the Staff lookup and you should have the ability to sort them.