|XP is just a number|
Hi jekyll and welcome to the monastery,
I think you'll receive answers from more experienced monks (and you are receiving it: i'm a sloow typer..), monks with a better overview about programming languages than me.
Anyway in my experience Perl5 seems not to be phased out, not slowly nor fastly, in the future. You can see yourself how many releases of Perl have been issued in recent past. Also the community seems quite active (see CPAN and others). Also some good new things have been released or upgraded in recent past (see PSGI-Plack, Moose or Moo, Mojolicious and Dancer..). Also new book are arrived with a new view on the Perl language (see the online version of Modern Perl).
Perl6 seems to me to be exactly another thing: is not Perl5++; is Perl6, a totally new language. It is not entirely arrived, even if you can play with it and many monks (not me) play and discuss about it. I dont think Perl5 will be dismissed after Perl6 official release. By the other hand Perl's decline in respect to 2000 year is noticeable, but this is another story. If you search this site for nodes with 'dead' or 'decline' in the title you can get a big picture and different points of view.
In short: yes!! come back to Perl!
There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.