In my opinion the new co-pilot's licence is nothing more than an inevitable consequence of the advances in aircraft and computer technology in recent years. The days of two hairy macho men hauling a converted WW2 bomber around the skies, fighting with towering CBs while feathering a flaming Pratt and Whitney a la Ernest Gann are long gone.
It has been recognized, and rightly so, that there is very little in common between hand-Flying a Seneca single pilot IFR and Operating a modern transport jet multi crew in a highly regimented environment. It could even, and has been, argued that flying one is actually detrimental to the other. This was not, however, always so; the airline pilot of the 1930's almost certainly came from a military background. He was used to being in charge. In civilian life he flew a ponderous, sub-sonic machine with a basic autopilot and a Boy to help him. The Boy had a head full of books and a basic commercial ticket and had even demonstrated that he could bang a DC3 down at Croydon 5 times in a row without breaking anything. He was an apprentice and would spend several years learning his craft from his Captain (Captains often kept the same co-pilot for months at a time). He was "brought on" as the Captain saw fit - a landing here, a take-off there, maybe even a closely-supervised NDB approach.
The trouble with this method of instruction was that it was unregulated and was totally dependent on the teaching skills of a man who often resented having to spoon-feed an apprentice who he saw as of little or no practical help. The problem came when the apprentice saw the Captain making a mistake. Should he speak out and risk a tongue-lashing and possible curtailment of his career or keep quiet and hope that the Captain would see his error in time....? There were many accidents that could have been avoided if the crew had worked as a team.
Fast forward to today. Transport aircraft are now highly automated multi-million dollar pieces of kit. The sky they fly in is increasingly crowded, particularly around the major airports and the airlines run on miniscule margins, relying on high turnover to generate the necessary cash to stay afloat. In this compo-mad World we live in, even one crash is likely to be enough to put an airline out of business. A computer will fly a modern jet far more efficiently than any human but the public still like to think that there is a man who will take control if things go wrong. CRM has massively reduced the instances of avoidable accidents and low houred pilots now enter service rated on type and are the product of a regimented training process; two complete strangers can now fly as a team from the minute they meet and seamlessly change to a new partner if required.
The odds of a co-pilot actually having to take manual control of a modern jet transport aircraft in an emergency are just about nil. The job requires different skills to those of 50 years ago but the basic training format has remained much the same. The present system is still relevant to those pilots who wish to fly single pilot air taxi in a piston twin although this market has seen a large decline with the advent of the Low Cost Carrier. As far as I am aware, commercial pilots of the future will have to make a choice at the outset of their training: Airline or GA. The training road post-PPL will fork and the two roads will not meet. It is likely that only airline-sponsored candidates will fly airliners as it just won't be worth the risk for a self-sponsored student to invest in a co-pilots licence.
The GA route will still be there but without 700 hours TT minimum it is unlikely that a newly-qualified pilot will find a wage-paying job. The co-pilot's licence is coming - it suits the airlines for all the obvious reasons, but it will take several years before it is unilaterally implemented. In the meantime the airlines still need to fill those right hand seats..............