Disc brakes do stress the fork more, hence the need for through axles.

Disc brakes are off to one side. Rim brakes are centered. Offset => twist => torque.

Disc brake calipers mount at the dropout. When you brake you the calipers pull on the disc, and the disc pulls on the calipers. With rim brakes this happens at the crown. Dunno if this is good or bad since the crown is already stressed.

Disc brakes tend to twist the wheel out of the dropout, which isn't usually a problem with rim brakes. We have learned some things from MTB.

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Disc brake calipers mount at the dropout. When you brake you the calipers pull on the disc, and the disc pulls on the calipers. With rim brakes this happens at the crown. Dunno if this is good or bad since the crown is already stressed.

Offhand I'd guess it's not bad. The there is the force pushing the dropout back towards the frame, putting a bending load in the same direction on the crown. The caliper force is similar but in the opposite direction and with a much shorter lever.

Will the first iterations of disc brake road bikes/wheels be great aerodynamically and weight? No. Once a company makes a light/aero disc brake bike/wheel combination, someone will inevitably cite this thread.

However, to think that the first round of design will be the end all/be all is foolish and short-sighted. Unless the fastest (professionals) adapt new technologies you will not see the bike companies invest in the research and development necessary to make them better. From a design perspective disc brakes make sense as you now have components that serve ONE purpose, stopping the bike. Currently, wheel manufacturers HAVE to make compromises in order to develop wheels that balance weight, aero, and braking performance. There is NO such thing as designing a product that performs 2 distinct tasks perfectly. Disc brakes allow the rim to be developed to serve its purpose, keep the wheel in contact with the ground and be as light/fast as possible.

I am not one to support change for changes sake, but the evolution of biking is inevitable.

Cling to your 9-speed drive trains and call them superior. I'll grab my popcorn and watch how this disc brake thing shakes out in the pro-peleton and IF disc brakes become the de-facto standard in the pro-peleton, I'll begin converting as most others should.

Ummm, plenty of great engineering is having a component perform multiple functions. Yes, a single component may not perform two distinct tasks perfectly, but it may be a better solution than having two separate components. Yes, getting rid of braking on a the rim may increase the performance of the rim itself, but will it increase the performance of the wheel itself? Of the bike itself? Just looking at the wheel, the new wheel shapes, I do not see how getting rid of braking would make the wheel more aerodynamic, the shapes really do not care about the brake track. And you need to add more spokes to a front wheel, so now the wheel is less aerodynamic as a whole. And that is without figuring in the extra aero drag of the disk, sure you could make the disk more aero dynamic, but then you decrease the cooling of the disk. Sure you could make the disk more aero-dynamic, but then you have to figure out the heat issue, so you can add a bigger disk which will be heavier. This is even without talking about the caliper and its cooling. People keep talking that integration will solve this issue, but I am not sold on this because shielding the caliper from the wind is going to cause heat issues. When you brake you have a certain amount of energy you need to turn into heat. With disks brakes, you put this energy into a small amount of mass, which means the temperature is high. The bigger the disk, the lower the temperature at the end of braking. So to reduce aero drag, you may want a very big disk, so the caliper can be small and be very aero because it does not need much cooling since the temperature is low. Well at this point, maybe it makes sense to use the largest disk you have, the rim itself.

I think people in this thread that a less keen on disk brakes understand compromises very well. They are the ones asking if a possible improvement in brake modulation is worth the costs.

Disks may make sense, but right now there is nothing

Fully understand and agree with what you are saying with the back/forth between the pro and amateur racers. You make a very good point that the pro's are not ALWAYS on the fastest gear, simply because their sponsors want them on the companies gear. However, I do feel like bike companies have a vested interest in their bike winning tours/stages/races, so they will invest in refining the design for racing.