I've always wanted the ability to play any combination of maps, whether they be official or user-provided. The campaign sort of allows you to do this, but not with the level of control I'm after. A simple example: I'd like the ability to play US & Canada. Or perhaps the opposite could be an option as well: Play all of Europe, but exclude Austria. It would be nice to have options like this without having to create your own map every time you wanted a different combination of countries.