If the rumors are to be believed, the M-variant 7 Series would have a version of the turbocharged 4.4-liter V8 currently in the 750i, but tuned to 450 horsepower. Power would be sent to either the rear wheels or all corners via BMW's xDrive. The question remains, though, what would happen to the Alpina B7 if this car were to come to market? All the added power and handling seems to fall right on top of the B7's piece of the 7 Series pie. Its future would remain to be seen.
Also in the rumor-mongering was word that there could be an entry-level 728i, employing BMW's N20B20 turbocharged 2.0-liter mill, albeit with the help of an electric motor. Such a vehicle would be slotted below the current 740i and positioned to take on small-displacement hybrid flagships from Audi and Mercedes-Benz.
Remember to take these reports with perhaps a few grains of salt; but its interesting to consider the possibility of BMW expanding the 7 Series lineup in both directions.