People I know want castles for storage. They usually have another location, as well. If we had a smaller castle, for those who do not like to customize, and allow 18x18 to have greater storage, like a castle, that would be great!
We also have so much space that does not allow any housing. If we had a few special spots added, that would help crowded areas. I would like to see them add a second house to each account. Possibly a small plot. Say if you have 18x18 or less you may also have one in the 7x7 to 10x10 range.