The 4 series concept looks good overall, except for the exhaust pipes. But obviously, that won't be an issue for any M4 or M3 since BMW usually have something completely different for their M cars.
It's an exciting time to be an M enthusiast. Since we knew the M4 was gonna look good - it comes down to performance. If the new M4 can raise the performance bar then I think the M4 will be a great car.