The german automakers over at M Performance are working on a hotter, meaner X3M powered by an in-line 6.
This X3 M is most likely to be powered by the M3/M4 engine (at least that's what it sounds like in the video) which will probably push out 400-500 Hp (300-400 Kw). The X3 M will also have a tweaked chassis, tweaked steering, larger brakes as well as sports suspension to help it around the corners.
As well as the power, BMW will also upgrade the aesthetics of the car, making it more aggressive. As for reveal dates, it'll probably be after the regular X3 is revealed in the second half of 2017.
Spy footage: AutoEvolution