(Also, dear readers, please don't think I'm ignoring you by not responding to recent comments on this series. First, it's conference season in the Land of Publishing, so I'm short on time; second, I want to foster as much of a debate between you folks as possible, and it gets complicated if I keep gallivanting into the comment arena to clarify or expound.)
That said—on to the exciting and terrifying future!
The Big Shrink (Publishers)
Over the next decade, I expect publishing to become smaller. Not in the sense that there will be fewer retailers and publishers; on the contrary, I think there will be more (see Consolidation and The Independent Renaissance, below). What I mean to say is: the giants (that is, the Big Six) will need to scale back their operations in order to remain profitable, and this will probably result in a net loss of jobs in the industry.
As the shift to e-books continues, there is/will be a temporary need for more employees at large publishing houses (chiefly for e-book conversion and on-line marketing). As publishers streamline their process, however, not only will they no longer need additional staff for the sale of electronic media, they'll actually need fewer personnel as the print runs and sales of physical books decline. Increases in overall title count may counteract this to some extent, but as everything from production to warehousing scales back, fewer people will be necessary overall.
Additionally, I'm predicting that the industry will consolidate somewhat (see below), meaning that jobs previously offered by publishers may increasingly be available with agencies and retailers.
As print runs decrease and e-books become the norm, it will 1.) be increasingly fiscally feasible for smaller operations to turn out a greater number of books, and 2.) no longer require that there be so much specialization and segmentation within the industry. A new, "boutique" literary enterprise employing a few literary agents, editors, tech gurus, and a small staff of on-line marketing and sales folks will be able to do the e-work currently undertaken by individual agencies, publishers, and retailers. Why sign with an agent, have him/her pitch to a house, and have that house deal with the logistics of selling it through myriad channels (often requiring greatly varied and/or incompatible information and file types) when you can get it all in one place?
Amazon already maintains in-house editors, and the Wylie Agency's Odyssey Editions fiasco telegraphed the intention of (at least some) literary agencies to take on roles that were previously the province of publishers and/or retailers. I think this signals a shift toward greater consolidation in the industry over the next ten years. Whether this means Amazon will be taking unsolicited mss or Simon & Schuster will open their own e-book store remains to be seen, but I think this niche will be filled by companies that already have a strong toehold in the digital market.
The Big Shrink (Retailers)
With the rise of electronic media and on-line retailers like Amazon, brick-and-mortar chains are under enormous pressure to adapt. I've previously likened the current environment to the Cretaceous era immediately preceding the mass extinction event: smaller/independent retailers are the scrappy mammals, brick-and-mortar chains are the dinosaurs, and Amazon (or Internet book retailing in general) is the comet. I don't think this is too hyperbolic.
Unless big chains like Borders—which, according to Publishers Lunch, will be seeing another round of layoffs and store closures—and Barnes & Noble can move a sufficiently large percentage of their business to the Internet, they won't (à mon avis) be around ten years from now. Eventually their operations will shrink to the point where their offering of a physical storefront is outmatched by independent stores' ambience, personality, and community involvement (see below), and they'll likely transform into an all e-operation, selling physical books via the Internet. Since Amazon already does this better than they do, I imagine they'll simply go out of business.
The Independent Renaissance
Finally, meine Autoren, I believe that the combined effects of e-book popularity and brick-and-mortar chain downsizing will lead to a resurgence of the independent book store. Offering everything you can't get from Amazon (locality, community involvement/events, readings, rare or limited edition physical books, &c), they'll expand to fill the roles they lost with the rise of the major chains in the early 1990s. But! More on this tomorrow.
Questions, (dis)agreement, conspiracy theories? To the comments!