We probably won't see a BWB unless Boeing gets the Pentagon to spring for a tanker and/or transport version first. The current aerospace industry is very conservative with its own money, and I doubt Boeing (or Airbus) would spend that much on a concept that has yet to be tried. The spirit that built the 707, 747 and A300 is largely dead. The A380 and the 7E7 have important, but incremental advances. The advances on these planes have largely been proven elsewhere first.
Building a new civil transport is enough risk on its own. That is why you won't see any major unproven tech on a new civilian airliner. The 7E7 has some new stuff, but the vast majority is new only in the sense that it has not been used in a civilian airliner before. A major configuration change such as a large BWB will certainly be tried in a military aircraft first. And no, the B2
and its predecessors do not count. There were not many built. The B2
is nothing like a civilian airliner. Most B2
technology will remain secret for a very long time. A transport or tanker BWB would look very different, and that is the kind of military BWB that could blaze a trail for a new kind of airliner.