On MTV.com you can find an Interview with Jeff Kaplan, Lead Designer at Blizzard. He talked about the backgrounds of developing The Burning Crusade and also mentioned player housing:
"I think housing can take 'World of Warcraft' to the next level," Kaplan said. "I want to make sure that when we introduce player housing to 'World of Warcraft' we do it right and give the feature the credit that it deserves, which is a massive amount of production time on the programming, design and art time. It's something we actually wanted to do for the original shipping game."
Read the interview here!