Delta now uses barcode technology on the boarding passes. I wouldn't be surprised if they have plans in the future to have a system where Medallions on a confirmed itin with no changes can proceed directly to the boarding door, flash their card, show their ID, and an express BP with their seat number is printed. They then proceed directly aboard.

I believe AA has tried this in the past. Anyone care to comment?

This is totally a guess; I have no real inside info on the matter.