There's a huge forum thread over on the forums right now (though it's been going for the better part of a month) about Blizzard putting in more for roleplayers -- player housing, surnames, and "a more interactive world" are all asked for, and much later in the thread, Nethaera does weigh in with a nice long statement about how Blizzard is dealing with all of this stuff. The bottom line, as always, is that there's only so many hours in the day, and Blizzard has to prioritize what gets worked on. And as of yet, neither player housing nor surnames or any of the other suggestions have made their way to the top of the list.
Which makes sense -- as many roleplayers as there are, nobody would really call them the primary audience of the game. There are definitely other games out there that are much better for defining a character. Which doesn't mean that we'll never see these things ingame -- player housing has been wanted (and promised) for a long time, and surnames are something that's common in almost every MMO but World of Warcraft. Neth just says that it's a matter of time, and that while player housing is still on the horizon, the world of Northrend will be more immersive and interactive than the rest of the game so far. Which is good news not just for roleplayers but for everyone else as well.