The question that rests like a gun to the head of the MMO industry.

What do you do if the perceived value of content reaches zero?

Value is a purely subjective measure, a comparative measure as to what is most worth your dollar. We have two measures of value, the natural and most common measure, and the more objective measure. The first is a comparison of what we pay for similar things, the second is what else we could be getting for that same amount of money.

MMOs as they stand are largely a content delivery mechanism. Their numerical and mathematical base being also the core of their user interaction means that their game play is rarely a content generator, such as you would see most aptly in Force Unleashed for example. What this means is that the player base requires a constant stream of new content, which with a maximum efficiency team should be produced in roughly O(n) time. O(n) time means O(n) pay checks, and while hiring more people would allow you to produce more content, you can't hire more people to produce the same amount of content faster until you are dealing with overarching story plots that can actually be subdivided into lesser partitions.

What all this means is, your product's intrinsic value is tied to the content delivered. The cost of content has a flat bottom, where each equivalent sized package of content costs a certain minimum to create which cannot be reduced. Thereby any equivalently "sized" game must cost at least the minimum cost of the associated content to create, with the game's engine, design, and core game play programming being added on top.

Ironically, although the quality of content often scales the cost of generation upwards, for professional level work, people generally pay roughly the same amount for any equivalently "sized" package of content regardless of quality. The monetary gain usually being manifested in number of purchases, rather than quality of purchases.

The baseline price for MMO content has been $15 for a while now. However, with the proliferation of non-flat rate business models, and the rise of user generated content being passed from a purely hobbyist vantage to a business model in itself, the baseline perceived value of content is approaching $0. It is important to note, however, that it is not the perceived value of any particular "package" of content that is approaching 0, it is the perceived value of content as a whole. Also, more than any particular business approaching any particular model, it is rather that the sheer amount of content available is so overwhelming, that content is losing all value associated with rarity. Having access to content of almost any sort is easy and free with the current climate of the internet.

My personal answer:
Much like novels, we will grow and adapt as consumers and businesses will, of course, fill in the voids. But in the mean time, some of the best in the industry will probably find themselves replaced by small operations that weren't even on their radar. Likely, launching without full content will become even more of a death knell than it is now, as it will be assumed that the game has full content and only the quality would set it apart as a worth while purchase.

But there are deeper aspects to this as well that don't fit very well within the current market overview. For instance, the very model of an MMO as a content delivery system will have to be reworked, at the very least it will become incumbent on them to act as content generation systems. User generated content as we generally refer to it probably will not be at the core of this, instead it will more likely be emergent rule sets designed to evolve alongside the players.

At least that's my $.02.