I have a friend working on the Aerion project which seems really cool from a technical challenge standpoint. The bizjet side of things seems to fit the supersonic thing better (customers are already paying otherworldly sums for travel, and are likely to be quick to get in line for the new "one up" on their peers), but I'm still curious how they'll handle the overland noise aspect. It was my understanding that aside from fuel consumption, sonic booms were the main thing that limited the adoption of supersonic aircraft for travel purposes. I've worked near Edwards AFB and while the sonic booms were cool when they rattled the hangar, it would be way less cool rattling my house at 2AM.
I know NASA and others have worked on aerospikes etc that are supposed to make things quieter, but I hadn't heard of any major breakthroughs that would completely eliminate the boom.