I don't know what to feel about this. I never used the player house in Fallout 3 or Fallout New Vegas or any other game. It's a bit Bethesda to appeal to the players by offering a player house. Who wants that?
Having said that we are going to get houses and then I suggest that Obsidan goes all the way and do it The Sims-style. I'm not kidding. Having a house should of course be optional. But if you decide to use it, it should be highly customizable. I'm thinking the range somewhat like this: You can set a location in the game world as your partys focal point (where the party meet up and hang around), it could either be an Inn like the Sunkien Flagon in NWN2 where everybody hangs around. Or it could be a house that you have bought or been givien (as thanks for completing a quest), or it could be a house that you have built yourself. And then I think it would be great if customization of it worked like in The Sims.
I hate how it works in Bethesdas games where you are limited to choose between preselected furnishings. I want to be able to customize everything by myself. Otherwise, what's the point of it?
I'm also thinking that you and your party are going to travel alot. Maybe you are given som rare furniture on your travels. Maybe you help a king with some of his troubles and as a thank you he let you have the painting from your room at his castle (where you were staying whilst working for him) that you've grown so found of. And things like that.
It would also be cool to be able to have your own castle in a never ending game world. So that you have somthing to do after you have completed the main quest.
But it would have to be much more developed than how Crossroads Keep worked in NWN2.
I'm thinking full stronghold style! Have you palyed the first Stronghold game and Stronghold Crusader? They are great. You can set the taxes. High taxes makes the people angry whilst low taxes makes them happy. But if you decide to have high taxes (to give you more income) you can counter the peoples dissatisfaction by giving them more food and giving them gardens to walk around in and such thing.
And with this mechanism it is easy to be either good or evil in your role as a lord. You can have low taxes, severe punishments, low food rations and no gardens to walk in. That will make them work hard. Or if you decide to be a good lord then you can have high taxes, high food rations, gardens and joy for the people and no punishments. The negative here is that the people wont work as hard but because of the high taxes you will still gain money. That's how it works in Stronghold. And you can also arrange weddings and stuff. Religion is also a factor. I forgot to mention that.
Edit:
About the weddings. In PE you are going to travel alot and you will probably encounter royals and nobles who wont allow their sons and daughters to mary just anybody. But if you have been given a castle of your own it would be possible for you to mary the children of higher ups. Or something. All I'm saying is that this castle/house feature could be an integrated thing in the gameworld but that it has to be optional for people who doesn't want a house or if they just wnat a room to dump their stuff in.
Edit2:
It would also be cool if you could open a store in your house and become a merchant. Or being able to build your own merchant empire. Just throwing out ides here.