I don't see this ever happening, as Intel would not likely be interested in generating ARM code in their compilers (at least not since divesting themselves of Xscale, (nee DEC StrongARM), a long time ago.) gfortran is probably your best bet there.
It is hard to tell the effective difference between a NUC and a RPi unless you want the add on boards for the RPi.
The NUC is cheap and effective, I tried both for an experimental project in the snow of Iowa, the RPi is good, but it has problems with some attached instruments and then getting the NETWORK to run. READ IT WILL NEVER WORK. We spent a lot of time on this problem, we could solve it with the NUC but not the RPi and even our LINUX guys gave up.
Interesting the RPi is only slightly slower than NUC using MONO and multiple threads.
it is a good little computer for a 14 year old - for a real use spend the money and get the i3 NUC.
The NUC works well in cold conditions and has a very nice reboot feature so it runs continously. Our biggest problem was the modem's, we solved this problem - but the workable modem solution for remote deplyment is more expensive than the computers.
I would love Fortran to run on the RPi - but not for real use. But children should learn fortran.
Sure - a NUC is a full PC. It can run Linux, Windows or most anything else that will run on X86, as long as drivers for the embedded components (video, audio, networking) are provided. I have two NUCs at home.
We use our NUC's all over the world, they are great and yes they run Intel Fortran, although one of the Intel Reps here was a bit surprised that Fortran ran on the NUC. But the latest NUC's are based on the chips required for Fortran.
A core i3 NUC with a SSD 1 TB is as good as most laptops under 1000.