Python - So as Perl,PHP were replaced by python, so too will Python be replaced. Example: Groovy is a dynamic/statically typed language on the JVM that integrates 100% in Java but has a syntax similar to Python (in alot of ways).

Swift - Its only around as long as current models of Apple want it around. Replacable by the next big thing they decide to embrace

PHP - steady downfall

C# - Microsoft specific libraries... STILL

Objective-C - Apple specific libraries