Although I think it would be cool (Since I dont share an account anymore)....at the same time, I could see this causing a few problems for those who DO share their accounts...like siblings.

I lurve mah sister, but I'm sure she would agree with me that we'd each want our own house.

We used to share our FFXI account. And I'm sure there are people now that do as well. But! Like I said, it would be cool to allow alts to enter my main's house....I used to make fanfiction of all of my characters working together.