Thanks Michael S for looking into it some more. Are you thinking about it because you see a need for some means to load in one hit or just for the challenge of the solution?
Michael M/Martel ...if I'm right you are the original/main author? If so thanks to you and any other contributors, I have been getting to grips with setting up routes and it's working out nicely, improving urls and cutting down on files as I retro fit a currently running website.
I'm picturing the following vague, untested and speculative use case:
Via an admin form a user can add new routes, eg:
Name: privacy
Controller: business_article
...which along the way would be interpreted as something like...
$router->addRoute('privacy', 'privacy', array('article_name' => 'privacy', 'controller' => 'business_article', 'action' => 'index' ) );
This would allow them to create pseudo static articles. What it would need is a storage area and therefore a means to load from that storage area so yes in some ways a route config of sorts. From my browsing of Django they seem to have this idea in their URL dispatcher and PythonScriptForParsingUrlConf.
Another wildly speculative idea that could spin off from a storage file containing routes is a means to autogenerate stub files for an application based on those configurations. I'm thinking of the fusebox wireframing tool idea and how in theory that route configuration would have enough information to kick start the file generation for a project.
I don't think this should be in the RewriteRouter itself. It is trivial to implement outside of the router just by doing a foreach loop which does a $route->addRoute()