Answer
No, and they probably never will. if they do it will be called an 8 series if they keep labeling cars the same. the 6 series coupe and convertible are the 2-door version of the 5 series. the 3-series might be the only exception to this rule. on the new e90 chassis (2006 and newer) they might keep calling the 2-doors 3 series, but they will most likely call them the 4 series.