C# is nearly twenty years old, and is still developing at a rapid pace. As more people switch towards .NET Core, I can see more people adopting the language and framework. On the same stack, I can also see PowerShell remaining for a long time, due to its scripting power on the Windows platform. As long as Windows is around, PowerShell will stay and continue to evolve.

Alongside these, I can see Rust expanding its reach, probably not to general purpose developing, but taking over more use cases from C++.