One thought, about the fight in the late 60s, early 70s between Europe and the US is that UK/France bet on Concorde, teh US on the 747. Europe went fast, the US large, and large won the commercial battle. There were various reasons for this, and there were good reasons in the late 60s for believing that there was a market for both. Concorde does now have its advantages, and some companies use it for sound business reasons - the time spared is worth the money to some of their executives (which compared with first class on a 747 is little premium).
Now we come to 2002. Boing bets its commercial division on a small, transonic (it is not subsonic - Boings comment was incorrect) aircraft, Airbus on a large subsonic one (note all contracts bar I think 1 so far signed the aircraft are 50% British, not 20% - they will fly with Rolls Royce engines).
My first impression of the Sonic Cruiser, having recently taught Principles of Flight was that the 15% saving in time could never justify the additional wave drag of transonic flight (this is the importance of it being transonic - wave drag peaks at these speeds). I thought I may be naive in my lack of knowledge of aerodynamics, but at Farnborough I was cooling down in Boing's air conditioning when I bumped into someone I knew at university, who had studied aeronautical engineering. He said he was there to laugh at the sonic cruiser. It was his opinion it would never be built in large numbers. We shall have to see!
Note also that A380 may replace Concorde. If (a big 'if') they can fit some sleeping cabins on for a viable price then sleeping onboard would save similar time for the busy executive, leaving at night to arrive refreshed in the morning.