For years, the sportiest 7 Series in the U.S. has been the Alpina B7, which has been deeply breathed-upon by the namesake tuner and presented through authorized BMW dealers. Most lately, Car and Driver reopened the conversation just last month.
According to the report, while BMW has long sustained that it wouldn't make a 7 Series M, "sentiments shows to be changing, especially with Willisch's complement in China also lending his support." Of course, if BMW builds such a model, that doesn't denote we'll see it in the States, but Willisch seems bright about our chances.
No schedule has been set, and BMW has been occupying its time with the just-revealed 7 Series refresh (and the M allotment is still busy readying the next M3), so if an M7 is in the cards, it wouldn't shock us if we had to stay until the next-generation model's appearance.