Another update:
perldocs are rather flat and should be IMHO better displayed with "woman.el" (man doesn't work on windows).
As it turns out, this is already available. Not from Emacs nor ELPA/MELPA, but there's Emacs::PDE on CPAN. This distribution provides, among other tools, M-x perldoc which is using WoMan and works quite fine on Windows. Even better, there's a command M-x perldoc-tree which offers all local docs in a nice tree view.
This, of course, makes a refurbishment of the perldoc stuff in cperl-mode a lot less interesting.