My ideas:

A rats map. Anyone can make one, relatively quickly. They're easy to build, but hard to be original.

An upside down map. Most mappers ignore their ceilings while mapping. Their floors always look better. A map turned on its top, would encourage mappers to focus on their ceilings, while also making them navigable.

A theatrically based theme, such as a circus.

A seven wonders of the world map.

My personal opinion on time limits is this:

Depending on which current mini-comp is up, the amount of enthusiasm would dictate its ending. Say, that the FY idea was the current event, the comp would have a short time period due to the lack of it drawing any real crowd. Of course, if my idea flies, the winner of each event will have a great say in the next event, and that person may want a FY map comp.

Anywho, say the bridge idea is up and 10 people genuinely dedicate themselves, then a much longer time frame would be ensued. For my part, I want each even to run no less than 2 weeks and no more than 2 months. Otherwise, the idea for "Mini" would go down the dumps.

At this point, I dunno exactly how much influence I will have over this idea. So anything I mention hereunto, may be totally ignored.

I have entertained the notion of a prefabbed city. A real city where each person builds a fully functional building as a prefab.

Consider this, if we managed to make 100 buildings, there'd be almost an infinite amount of ways to configure them into maps.

I know its an absurd notion, but I still think it could be done, especially if we simultaneously had a prop prefab section. That way we could have the mundane things like fire plugs, mail boxes and phone booths for our future city.

Then, if someone or one's built some custom skies, we could have many daytime or night time cities.

Well, its a notion I have had.