"Perl is an excellent candidate, especially considering how work on Perl6, framed as a complete revamp of the language, began work in 2000 and is still inching along in development."
This does not imply that Perl is on its way out. I don't use the language myself (I despise it, personally), but I know many who use it on a daily basis. It is still a go-to language for many programmers (albeit, who may no longer be in their 20s) who need to quickly hack together a test harness for a larger system. It could merely be that Perl is "complete" for applications where it is useful. Further revision is no longer necessary.
Also, I'd hardly say that C++ is on it's way out, even though C++11 took so long to be ratified.