Issac Asimov opined in the preface to "Asimov's Guide to Shakespeare" that the English language has changed little since that time simply because we wish to read The Bard in the original. I think that Perl 5 will be with us for a long time for the same reason. It really is that good of a tool.
Moose is providing a bridge to Perl 6 but at the price of feeling "heavy" as it were. Moo is advancing Perl 5 while still being "perlish". Perl 5 will be viable and even grow for quite some time thanks to that.
You must always remember that the primary goal is to drain the swamp even when you are hip-deep in alligators.