C, C++ and Go are going strong. All operating system kernels we currently use are in C, as well as most low level drivers and libraries. Most PC client applications are in C++ including most video games. Common web servers are in C. They will be around for many more decades.

Go already replaces Java and dotNet as a leaner more suitable server language in some companies. Nodejs and Go apps (+ JS in the web browser) replace older CRUD web apps written in Ruby/Python/Perl. Most languages will stay around for a long time, although a less popular for beginners.

Java and dotNet will have a harder stand. On the one hand dynamic typed languages like Lua, Javascript and Hack/PHP with their JIT compilers are already (almost) as fast and allow developers to be more productive while still offering optional typing when/where speed matters. On the other hand new static compiled languages get more approachable (Go, Rust, Swift), are faster and use less memory.

Paradigm shifts surfaced exotic languages and trends. So Erland/Elixir, Go, Nodejs and others are very popular for todays web services.