Given that after 9/11, airlines were more interested in saving money rather than getting people to their destinations quicker, Boeing abandoned plans to produce its Sonic Cruiser in favour of the 787.
This week's Flight International has an article "How the airline market focus changed" in which it asks if Boeing would be a different company today if it launched the Sonic Cruiser ahead of the 787?
http://www.flightglobal.com/articles/2007/07/10/215431/sonic-cruiser-a-different-boeing.html
Boeing would be a naive company by not listening to market trends if it went ahead with the Sonic Cruiser, don't you think?