Of course, we knew this was coming.
Even for a teaser from an automotive company, the clip here is pretty vague. In fact, we only know that we're looking at a new M car because of the title "BMW M is preparing something new". Given what else is going on at BMW, we're all expecting this will be an M version of the 4-Series, essentially making it an M3 coupe. That does sound like some good news, despite the anger coming from the BMW faithful over the decision to call it the 4-Series.
By all means feel free to draw your own conclusions from the video, inasmuch as that is possible. And if you think it's something else, then don't hesitate to speak up.