Suggestion for Best practice for Menu rbac

I’ve been thinking about making a Menu module recently. If I were to write it some things I would like it to include:
* A Menu device that implemented various Menu Handlers. Each handler would represent a front-end framework, so the same menu definitions could be ported across websites with different frontends just by changing the handler
* A component-based definition for each menu, probably building on CodeIgniter’s HTML helper
* Auto-generated menu states and breadcrumbs, especially using the handy new url_is() function
* Optional filter so the menu could be injected without having to change your View Layout