make no mistake, tablets are the next wave of computing for the mass market. the article basically says that we're in the lull between saturating the early adopter segments and addressing the majority segments, i.e., we're peering into the chasm. it's not a reversal of the market toward pc's.
the reasoning, in my reading of the article, is that the tablet market materialized so quickly that most manufacturers (including apple) didn't have enough time to anticipate future market needs beyond simple consumption devices. now that tablets are "a thing", manufacturers are regrouping to provide the next set of features and functionality that now seem obvious to deliver but are more complex. the timing is also dependent on a number of technologies having advanced enough (processors, displays, batteries, software toolchains, ubiquitous connectivity, etc.).
even in the enterprise, computing devices are moving toward being appliances, which is where tablet technologies fit in (note that mobility is not a key priority for a good chunk of the enterprise). your average salesperson, accountant or analyst has no appetite for managing the device itself, and ios and android (to a lesser extent) are designed to hide away this complexity. 15" tablets with wireless keyboards/mice and robust remote management capabilities will replace (or converge with, if you prefer) most desktops & laptops in the enterprise in time. many outside sales teams are already on tablets since mobility & connectivity trump power for outside sales.