Cycling out old material as new material is introduced
I strongly suspect that D&D will soon be following the model of Magic The Gathering. That is, older material will be "phased out" in order to make room for new material. I believe this for several reasons:
Power Creep: It's just plain good marketting, and Wizards demonstrates the minimum restraint practical. Like Magic, 4E is sensitive not only to the creep of individual powers, but, more consequentially, the possible combination of powers, which grows faster than exponential with the number of published powers. 4E may be even more sensitive than Magic in this regard, as characters can choose exactly when to use a specific power, rather than depend on the luck of draw. Once a broken combination of powers is discovered, it can reliably repeated as needed.
Errata Explosion: In order to minimize or delay the unintended consequences of power creep, Wizards can issue errata. While the errata for individual powers represents a tiny fraction of the available powers, and grows proportionally to the number published, as noted above, combinations grow faster than exponentially, and so will the errata necessitated by those combinations. We are in the early, nearly flat part of that curve now, but it will become increasingly apparent as more books are published.
Inadequate Playtesting: Playtesting of 4E is already inadequate, and Wizards often chooses to ignore the results of playtesting. Compared to creating new material, playtesting has a poor return on investment, and works directly against power creep. Worse, as the number of power combinations increases, so does the playtesting required to minimize abusive combinations. So as more books are published, the incentive to playtest, from a marketting perspective, decreases, while the need to playtest, from a game play perspective, increases.
The Spice Must Flow: Driving all of this is the need to sell new books.
I see two alternatives for Wizards when the inevitable happens. First is the usual solution, to issue a new edition in order to spike sales. However, I suspect that their customer base already suffers from version fatigue, and would be very wary of a 5th edition. Alternately, they can adopt a "horizon model," like Magic, where the oldest material is "aged" or cycled out in order to make room for new, fresher material. In that way, like Magic, the number of available powers and combinations remains roughly constant over time, and they can safely indulge in power creep for marketting purposes, secure in the knowledge that abusive powers can be introduced, but only remain in effect for a short time.
From Hasbro's perspective, there are two more alternatives. When D&D sales drop below a certain threshold, they can either sell D&D to another company, or simply stop actively publishing D&D and pursue other options with the brand name, as was done with Axis & Allies. Perhaps a series of board games, or boxed adventures sets, or even a CCG. Hasbro often stops publishing games for years, then resumes printing, like Acquire.
Smeelbo
