After studying the first photos
of the F80 M3 with its "power dome" we think that it may be a functional heat extractor vent underneath the camouflage. Let's analyze.
The shape of the bulge on the M3's hood is not the typical fully raised dome as seen on the E90/E92 M3 or E46 M3. Instead, it's a raised "U" shape with 3 raised sides while the area in between remains level with the rest of the hood. See the render below for a visual.
Assuming there is a functional reason for the hood dome in the first place, we can't think of a reason for this particular shape if the goal is to provide clearance for some engine parts underneath. However, the raised hood shape makes far more sense as a heat vent for the engine compartment. One only needs to look at the E92 M3 GT2 race car
to see how the shape of the F80 M3's bulge matches that of heat extractor vent on the hood on the E92 M3 GT2 race car. They are very closely shaped and sized (see photos below).
If this proves correct, not only has the F80 M3 gained a sportier look, but it will have the added benefits of extra engine cooling, as well as the extra induction and engine noises that will better flow out from under the hood to give the M3 an even better sound. Oh, and it also gives the upcoming M3 an extra level of awesomeness.
E92 M3 GT2
Render by Harold Wood