The three-and-out model, as a strict formula, is already dead; lifespan: 3 years (I'm giving DS some wiggle-room here).
Whenever a corporation (or anyone for that matter) makes a declarative statement about the future, consider adding a silent "as far as we know" right there at the end of it. In this respect, a 3-year run for a best guess isn't too bad.
Next year won't see a distinct 3-book setting release at all.
Ravenloft Roleplaying Game will get its own rulebook, which while possibly compatible with 4E, won't be a setting product in the exactly the same way that
Gamma World isn't one either. It'll be interesting to see exactly what the scope of
Gazeteer: The Nentir Vale content takes, but clearly won't be a model setting release.
And don't you want a highly detailed smaller region to start with, like Shadowdale or the Silver Marches?
This product is on the 2011 release schedule as the
Neverwinter Campaign Guide. So there ya go. No more
being slavish to the three product form.
Generally, I've observed that setting support following the initial release takes some mix of the following:
- Adventures
- Setting Porn
- Fiction
I think the first option produces the best results for actual play at a table (real or virtual)
by far. Greyhawk was built on nothing more than a thin gazeteer and some serious adventure modules. Latter-day GH setting porn was mild stuff indeed compared to FR and Planescape. I say this as someone with an entire shelf of Planescape boxed sets. FR, in addition to its volumes of novels and fluff, also had huge adventure support--
huge.
The best thing WotC can do to support the existing 4E settings being used in actual play, is publish good adventures for them.
As far as I know.