The near-monopoly of GCC was leading to stagnation. Clang's competition seems to have reinvigorated the GCC project, which is a fantastic outcome for users: two great compiler teams riffing off one another's improvements, and we all benefit from their work.
I don't know how much is impression, but on my side I felt like GCC was a crumpling mammoth. clang forced them to improve and at the same time it showed that gcc is not near death at all.