I second this idea, though at some airports with a lot of different security checkpoints (e.g. DFW) it might not be so feasible.

It also might be difficult to implement for practical reasons (e.g. training the DEN people to recognize credentials from every single airline).

Perhaps a single uniform credential could be identified and the airlines could give permanent ones to their elite members, single day ones to high fare pax.

I seem to recall seeing separate security lines for first/biz pax in some European airports.