I'd be curious to see a per-ward heat map showing actual player activity outside of their own plots of land, something that illustrated exactly how many people are spending time utilizing the neighborhood.

Player presence would, I think, be better off concentrated into apartment-like lobbies. Use the marketplace or a newly-created hangout-friendly area in each housing zone as your socialization center and get rid of wards altogether. Have a gate that accesses houses and lets you pick where you want to go (your plot, others' open plots). Players could move very organically from hanging out in the "lobby" area to the instanced houses -- it could be just a short walk away. With notes and at-home indicators, you could always know where the party was. I think it'd beef up general housing zone use and player interaction.

Yes, it'd suck for homes to lose their visibility but I think it'd be an acceptable trade off to reintroduce socialization and the neighborhood feel.