Stormind Harbor before Old Ironforge??

Q u o t e:
Why the decision to add a full new area to an existing city before finishing one that's almost done?

There are several areas in Azeroth that have yet to be completed. This is not to say that we never intend on revisiting some of these places. It's all a matter of timing and finding a way to fit in some of our older ideas with some of our upcoming content.

For instance, the Stormwind Harbor makes sense now to provide the Alliance quick access to Northrend beyond flying to Menethil Harbor. Just the same we're opening the Orgrimmar Arena to put it to good use for some new challenges in Wrath of the Lich King.

You may well see other areas in Azeroth of which we've yet to make use come to life some day.