Tom Johnson outlines the future role of technical writers. I agree with Tom ("I share the hope" is more accurate :-) that in the near future, technical information will be gathered via Wikis.
However, I am not sure that what I will be selling would be tutorials and other books.
By "tutorials" I refer to any kind of structured information set. Today, programmers and product managers deliver more structured text than ever before. It is structured, and it is structured in a way the customer would benefit from reading it.
More and more documents requires less and less intervention on my end.
I'd also replace the argument for endless documentation tasks with finding a new purpose for the tech writing role. It is true that "If you’re a tech writer for such a project, the documentation will be like a living child, always growing, maturing, asking harder questions, getting into more trouble" but it can go in opposite directions: let the tech writer boss it all, or forget using tech writers altogether. The writer has to constantly add value to the documented project. Not only to the project's documentation, but to the project itself. (hint: think of usability rather than of the code.)
As for delivering a clean text. The technical world is already writing in Globish. I'd guess it has done so from as early as 1998, but am not sure that it's OK to use present perfect tense anymore.
It all new for us, writers, but the future belongs to the brave, as it has always been.