mod_perl is not going to be "ported" or "updated" I argue. It is terrific for what it s/is/was/, but what it has become is an albatross around the neck of a doomed sailor. Apache has lost miles of market share to servers like nginx and lighttpd. Apache is still sort of the 800lb gorilla but the newer servers destroy it in performance despite not sporting as many features. I would never recommend apache or use it willingly today, plus there is no inertia behind Perl6 like there was for Perl5 in the 1990s so that level of dev integration tuits will not materialize.
The good news is, it doesn't have to. uwsgi is a fantastic application server layer, and there are others, to fold into any webserver and it supports PSGI so it's already ready for Perl and I am sure it could (or already does or soon will) work with Perl6 without too much futzing. Might be a little while to shake out though. I think there is debate about what the PSGI layers need to look like in Perl6 to support the strengths of the language.
Lastly: PHP is no longer rising. It's ubiquitous but it's done where it is, so I say; any growth trends are only a proportionate reflection of the growth of the Internet.
