If in the new housing system we are only going to be able to have neighbors via signposts (which personally I feel does not make for much of a neighborhood), then I hope the signposts indicate in some way whether our neighbor is home and/or receiving visitors.
Much better would be for our neighbors to actually somehow visually be aligned in a virtual neighborhood or street, perhaps separated by thin teleportation portals. I want to be able to "eyeball" down the street and see the cool places my friends have built, and have a shared space to interact in.
It's not a neighborhood if you can't have a block party.