I guess that M was feeling lonely. So the transformation of the M brand to join the AMG and S/RS club is well under way.
I honestly do not see anything from an engineering standpoint that would justify an M letter. However, BMW can charge a lot more for "M Performance" than for ZMP and ZSP put together. Milk it.
Meanwhile I just saw my neighbor cruse in the unreleased M 335is. LOL.
Let the argument begin about what a real M is.