BMW confirmed it will make a Grand Coupe version of the next 6-Series that is a four-door coupe (like the Mercedes CLS or VW CC). It is supposed to be different enough that it won't be like a slightly smaller 5-Series:
BMW greenlights Gran Coupe - MotoBullet.com News (motobullet)
BMW greenlights Gran Coupe - MotoBullet.com News (motobullet)