It's not entirely theory on our part as the devs have discussed the layer system before regarding multiple instances of the same zone. They are basically running multiple copies of one zone, but there is a limit to the maximum number of copies. And you are correct, it does not appear to be a simple task at all to add more layers. It's always sounded to me like less of a hardware issue and more of an issue with how the backend software was programmed.
In the last AMA, they said that they canned the new UI once they realized they wouldn't be able to have it completed before RoV was completed (and the majority of the staff were scheduled to leave the department.) There's a higher likelihood of seeing a new expansion pack than seeing the UI at this point.