First of all, I'd like to add an option to repositories to allow them to work without a cache at all. This means that, whenever a new tile is needed (i.e. not already drawn on the screen), Maemo Mapper will have to download it - it won't try to retrieve it from a cache database, because there won't be a cache database (for that particular repository). It's a bit of extra work, but I think it's definitely doable. But is it worth the effort?
Soooo... Idea #2 for Maemo Mapper 2.x is to support layered repositories.