Super critical wings like those on the 777 already allow localized supersonic flow.
The F22 is designed to "supercruise" and all supersonic fighters don't suddenly fall out of the air as they are going through the sound barrier.
What boeing is designing is most likely a supersonic aircaft optimized to the speed just below the speed of sound. That way they don't have any high speed buffet limitations and thus no "coffin corner". The only limit, other than economics, will be making sonic booms.
I know American Ailines is really interested in it. They would love to be able to do their tranlantic flying without a 3rd crew member.
1-2 hours over a tranlantic trip is HUGE in crew costs.
Cheers
Wino