The usecase is the following: being able to migrate a website with an existing directory structure.
The directory hierarchy can't be changed for SEO and other reasons.

For instance, the site has a file /news/recent/programming/newsweek20100312.htm and it could be processed as a pelican page, but currently it isn't possible to tell that the folder structure in /content/pages/ is preserved so the /news/recent/programming hierarchy could be achieved.

As a hack, I could use the category metadata changing the PAGE_SAVE_AS and PAGE_URL settings, but this only gets one more nesting level.

Proposal: Add a PRESERVE_CONTENT_HIERARCHY (= True) directive so the directory structure in content/pages/ is replicated when building pages.