Exactly! The product would have to be carefully designed to not be attractive to you (or to businesses that currently pay for business class travel), yet be attractive enough that people in coach would be willing to fork over additional money to get the product. (In fact, perhaps Delta might specifically exclude the PE product from corporate discounts and not allow travelers on corporate fares to "upgrade" to PE, unless they pay the difference between their corporate discounted fare and the equivalent regular, published fare. You'd have to be careful though, to continue to offer the product to corporate clients traveling for leisure, much as Delta offers leisure travel discounts to corporate clients today.)

As you observe, it is, something of a return to 3 classes BUT with a significant difference. If you look at leading airlines today, First Class is all about "over the top" indulgence (truffles, caviar, overpriced carbonated grape juices gone bad, chauffered BMWs between the terminal and the aircraft, etc.) Business Class is all about getting one from point A to point B in a reasonable amount of comfort so that one arrives at one's destination reasonably well-rested and able to go directly to work. Coach is all about volume - moving as many people as practical between point A and point B with with minimum transportation costs.

I'm trying to see whether or not there is a demand in that third class (Coach Class), only on ultra-long-haul flights (say 15 hours or more) for a slightly more comfortable travel experience and whether or not people would be willing to pay for it. In my vision, I don't ever see the product being offered on flights of less than say 8-10 hours (i.e., no eastern CONUS-Europe), and I'm not sure you could offer the product on anything less than a 777-class aircraft. (I suspect even the 787 might be too narrow. If the 787 BusinessElite Suites configuration is 1-2-1 and you can fit domestic first class-style seats into a 787 in a 2-3-2 configuration then it might work.)

In summary, I'm not proposing a "degraded business class", I'm proposing an "upgraded economy class".