We're writing it for the ground processing for data from a new space telescope. Personally, I wish I was writing C++ or Python, but it does allow scientists to start writing code much more easily than C/C++ does, though Python is now more familiar to younger scientists than Fortran. Python has the downside of a lack of stability, however.

Fortan is pretty painful to write in. The lack of an STL means writing algorithms yourself. There is no good set of libraries, so you have to write more stuff yourself.

The string support is horrendous. Most of the language is based around clumsy fixed size strings. I wish they would add a new flexible string type.

The compiler quality is not up to C++ standards. My code currently has some nasty workarounds for problems in gfortran. It's not good to keep discovering compiler bugs.

I also find it's much vaulted numerical capabilities overstated. Vectorization only works in simple cases. You can't drop down to using SIMD wrappers to fix this. It's nice to be able to pass arrays around more easily than C, however. A good C++ array library would be better, but that would require everyone to agree on one.