I too have bemoaned the reduction in Mavic braking surface thickness over the years; MA2 had about 1.8mm when new and Module 3 (a ~510g rim, remember) had 2.0mm thickness braking surfaces..... nowadays the standard (even on training/touring rims) is a miserable 1.35mm, and that is if they have not left any thin spots....
I've been waiting (about 15 years) for what Mavic call 'exalith' (but the rest of the World knows as Keronite, see google) to be industrially applied to 'ordinary wheel rims'. They have been using since 2011 on their top of the range products
http://www.bikebiz.com/news/read/keronite-important-technology-for-the-bike-business/011152.
I had some involvement with this some years ago; amongst other things I still have the world's first set of similarly treated suspension forks (which I ran for many thousands of miles) and a few other odds and ends including some prototype wheel rims in my shed....
So Keronite is a conversion treatment, like anodising, but it is much, much thicker and harder wearing. I doubt very much that it will wear out on braking surfaces inside 30000 miles. However any product that has this treatment on it must be further treated in manufacturing to remove the uppermost, rough, more friable layers of the surface. Typically this has been done by polishing using SiC abrasive, but in wear applications the surface condition will still change as time goes on. The most common result is that the surface becomes (microscopically) smoother as time goes on, and pores in the surface either unclog themselves or clog up with debris depending on what the conditions are. I have not been involved with this particular product development, but it seems to me that the surface has had some kind of additional/variant treatment to render it the colour that it is.
All hard-treated rims change over time, and/or behave differently in the wet; it remains to be seen how these rims perform in the real world. Quite probably the first sets of brake blocks could usefully be different to those that might be used subsequently.
So I am hoping, fingers crossed, that this will truly be a 'rim for all seasons'; lightweight, strong, durable, long lasting. Only time will tell!
cheers