We just came out of a decade of nifty language mania. What I learned is that languages are boring but problems are interesting. Algorithms and solutions are interesting. A great solution to a challenging problem is really interesting even if it's in the most boring language ever.
I have code on my machine written in C in the 70s because C is largely "done." People today continue to write interesting stuff in C. Neuromancer was written in the same language as Lord of the Rings and Moby Dick, too.
Of course, we're talking about pre-ANSI C where any function prototype without a void argument implicitly accepts any and all arguments.
I don't think Go is done. The active development speaks otherwise.