Beckett said:
With the number of books on the calendar, I'm not sure if they have the manpower available for a full-out, on-the-shelf-next-year development.
Most of those books list freelancers as authors. Also, the lack of editing quality and playtesting in recent (last 2 years or so) WotC titles indicates that their editing and playtesting resources may have been reassigned to other projects. Finally, Mearls was brought over to R&D as a developer, and he's hinted about the amount of time he spends developing miniatures and miniature-related products (Fantastic Locations, etc.).
As for SteveC's question about the minis market, there are actually three overlapping markets for D&D miniatures: role-players, collectors, and skirmishers. I know only one single person who buys minis and doesn't play the RPG. On the other hand, I know lots and lots of people who buy minis
only to use as RPG props and have zero interest in skirmish. In fact, there is one really solid proof about the skirmish game not being popular enough for WotC's liking: rather than pushing DDM any further as a tournament game, WotC is introducing a new miniatures game - Dreamblade - as their future tournament flagship, with a $20,000 tournament going on at GenCon this year. DDM has
never had that much prize support. In fact, prize support for DDM this year has been reduced from last year.
There is one other strong argument that can be made
against the prevalence of minis in 4E: D&D miniatures quality is on the decline. Heavily so. There have been problems with sculpts, paintjobs, illegaly leaked information and photos, packaging, randomness issues, typos on cards, typos on posters, torn maps, maps with erros, and so on, and so fourth. Furthermore, the booster price is set to increase next Spring, and many serious collectors have stated that they plan to reduce their purchases. Minis are too expensive for kids to buy as is; I firmly believe that it is the multi-case-buying collectors who have been driving the market, and if they stop buying, the game is dead.
Finally, previous DDM lead designer Mike Donais and other members of the team have been moved to the Dreamblade team, with Stephen Schubert taking the lead role of DDM. I very much doubt that they'd change the leadership and downsize the team if they were putting so much focus on minis as Eric's initial post implied.