I have visited a few of the neighborhoods around and since everyone has been discussing changes I thought I would throw this out. Any ideas listed here would be a major update change so it would probably never happen but here it goes.
What if neighborhoods didn't have houses, but have lots, all lots are the same size and you can put various houses on it. Lets say a lot has 4 housing spots on it. A small house costs 1 spot, a deluxe house is 2 spots, an estate(new house design) is 3 spots and a kinship hall is 4 spots.
Basically you could buy a lot and if you wanted small houses for multiple characters you could put up maybe 4 smalls, or a couple deluxe houses but they are all tied to your account for that server (meaning regardless who buys the lot it belongs to your account so if you delete that character down the line nothing is lost. You could even drop an estate plus a "servant's quarters" (small house).
This gives you the flexability of buying a lot and starting with a small house but when you have the money you can upgrade to a larger house without having to move out of the neighborhood (or somewhere else in the same one if your lucky).
Now I would also prefer to have a SWG style customization in the house where stuff can be placed pretty much anywhere and maybe leave the hooks idea for outside objects.
I kinda like the idea of 4 small houses you can position their entrances like a little mini neighborhood and maybe be able to have little roads connect all the houses.
Just an idea and probably not possible without a major housing overhaul but I though it sounded kinda neat.