The disappearance of the 6 Series coupe means that the midsize luxury coupe segment is all but abandoned. The only vehicle left is the Mercedes-Benz E-Class coupe. And if luxury buyers don't want that, they'll have to either upgrade to the huge, expensive Mercedes S-Class coupe, or downsize to something like a BMW 4 Series, Audi A5, or Cadillac ATS.
We don't think we've seen the last of healthy-sized BMW coupes, though. Over the past few months, we've seen BMW testing a new coupe that could be either a new 6 Series, or perhaps a return of the larger 8 Series. The use of either nameplate is quite plausible. One is already in use, and the other has come up in trademarks and alleged BMW model documentation. In short: stay tuned, coupe lovers.