secondary: Powershell has some cool features based on directory abstraction of recursive structures, like cd registry-key and navigating it like a filesystem.

IMO, the ideal approach for that would be to have a virtual file system layer, something that would allow one to hook his code into any function related to browsing the file structure. For instance, GNOME has GVfs for that.

Actually, I think porting Perl to work on top of GVfs, could be an interesting project.

primary: this question "glob an array?" would be trivial if we could chdir DH to a directory-handle which abstracts an array and glob it

Note that glob under the hood is loading and calling File::Glob, and if you study the code for this module you will see it already has hooks in place to support user defined opendir, readdir and closedir operations. But then, those hooks are not exposed at the Perl level!

Then you also have Text::Glob.