What's interesting to me about this is that no major airline wants to go supersonic, for two reasons. First, because of the cost of development, and, second, because you lose a significant fraction of business class revenue to your supersonic fleet, raising the costs of tickets for leisure travelers and affecting routing. However, you don't want to be subsonic if another carrier is supersonic, because then they get your business class revenue.

It'll be interesting to see what happens if they make it.