I think they'll do digital (or mini "bigature") sets. If you think about it, keeping physical sets around for several years during a TV show becomes very expensive- therefore the number of locations is kept low to keep costs in control. With the digital sets, they can create new ones every week without scrapping the old ones. If you have a scene that takes place in an old set, it only takes a few minutes (or hours) to break it out of storage as oposed to rebuilding it or whatnot.

For my money, the mini sets seem to look real without costing a lot of money to make or store.