Japan's space agency plans to launch an arrow-shaped airplane at twice the speed of sound high over the Australian outback as early as next month in a crucial test of the country's push to develop a supersonic successor to the retired Concorde.

From what I've heard, the concorde was not very nice in the passenger cabin. Boeing seems to be betting that people would rather have a more comfortable ride than a faster one. Not to mention the huge premium you have to pay to build and operate a supersonic jetliner.