For those of you concerned about land limits, or players running out of available land to build on, remember way back in Letter from the Producer LIVE 3, Yoshi-P mentioned the following about housing:

0:59:26 To prevent disputes over land, housing areas will be instanced. After the maximum number of houses are sold in one instance, players will be asked to purchase land in a different one. More instances will be added as necessary.
So don't worry!