I will try to keep this as short as possible, but basically I had the following idea in mind:
What if there was a new map status called "community" maps
(could be called something else like "priority" or "loved" maps, but I will just go with community for now)
Ever played fun unranked maps like Flower Dance, Escape With The Clouds, Routine, etc. and wanted to compare your scores with your friends, global or country but can't because the map is not ranked?
Well this is why we need something like community maps:
Community maps would basically be popular unranked maps which would be defined as "community" once it would receive an X number of favourites or kudosu. For example, if an unranked map would receive 50 favourites/kudosu, the beatmap creator would have the option to publish the map as a community map, thus activating the maps rankings to be seen publicly. They would still be able to work on the map to try to qualify it for ranked and in that case, the final ranked version would replace the community one, pretty simple.
Of course no pp would be given for playing these community maps which is an important factor to consider.
Currently, you can only view your friends score on an unranked map if they send you their replay for the map, which you would then be able to see under "Local Rankings", but this takes a lot of effort and a feature like this would definitely make unranked maps more interesting and fun.
Obviously this features would require the user to have osu! supporter
Let me know if you support this feature, what else you think could be done, if I missed something out, or why this would be a bad idea!