Hypertext may or may not become a common way for individuals to write. It may not even become a common way for individuals to read, in the sense that discursive arguments may not commonly be broken down into small nodes of nonlinear text as this one is, simply because hypertext may not prove to be particularly friendly to this kind of argument.
It does seem virtually inevitable, however, that much reading will be electronic reading, and that much of that will become more like web surfing to the extent that the reader will be encouraged by the nature of the medium to leap from document to document. In the best case scenerio, she will leap because there is useful and related material in another document. In the worst case scenerio, she will leap because the material is not immediately engaging.
Postman and Tuman present the worst case of this worst-case scenerio. But you don't have buy their entire analogy with television in order to interpret the clickable classroom as a loss that may possibly outweigh the gains. There is a good argument to be made that most of what we currently value in modern education is related not just to text but to print text. The cognitive growth, the contemplation and reflection, the ability to internalize thought processes through exposure to forms and structures, and perhaps even the ability to think with propositionalized arguments, may well be constructions of the print age which will be seriously compromised by extensive exposure to various forms of television-like "hoptext" (as Moulthrop calls it).
There are several possible responses to this scenerio, ranging from outright resistence to various ways of helping students to enter this new world with their eyes as open as possible.