I do not RP, and I have always found it kind of absurd, but I think that player housing would be really cool. It does not have to be complicated, just an instance in the city that becomes the house of whoever owns it. Every player gets to buy a house for 1000 gold in whichever city they choose about wow gold. The player must choose 1 home city, bound for the life of the toon (with an option to move at expansion packs) which I think would be a really cool because it gives you a really defining choice to make about your character. The player could then earn furniture through quests, gold, rep. etc. A more expensive house should be available about wow gold.

Add decorations through everything. PvP, PvE, the Achievements system makes this something tangible, with banners and trophys for all the achievements players can accomplish through all aspects of the game about World of Warcraft Gold. Stuff you can buy, stuff you get from world events. The biggest hurdle would be a basic redecorating UI, but I think that the framework exists in the same system we use to create banners and tabards. Hell, let people hire a butler that sells food and drinks to get cheap wow gold.

Make it really casual friendly, perhaps the casual friendly aspect of WoW. Lots of achievements that are severely limited in how much of it you can do in a day, so that the return on 1-2 hours of input is similar to 4-5 hours. Maybe even schedule the events needed for the achievement during key raid times. Give players the ability to make it their own as best they can. It is a great way to please the casuals and give them something tangible and demonstrable, that they can show off and be proud off about Wow gold.