Sadly after taking aerodynamics and turbine engine classes I highly doubt we'll be seeing supersonic commercial flight again. We just can't make engines or airfoils that are efficient at both subsonic and supersonic speeds. If you've ever seen Concorde take off you know what I mean about inefficient engines *cough* *gag*
This is not to say that we won't EVER have it, I just don't see it anytime soon. Besides, most people are pretty content with subsonic flight especially at 1/10 the cost.
And as for development, I really doubt any business, government, or investor with any sense would try something like the Concorde again. It was a botch on the highest of scale. Even when they charged an arm and a leg they couldn't recover the cost of R&D. Even after, what, 30 years of service? I imagine requesting billions of dollars to build a new Super Sonic Transport (SST) would be a hard sell to say the least.
From what I can tell, the future of aerospace is not in speed but economy.