I am truly sorry for people who (still) use a word processor for all the imaginable types of writing, as it is, in my humble opinion-shmopinion, a bad (or even very bad) compromise of several functions that can be performed far more efficiently by other, dedicated, software programs: 1) a sophisticated text editor (my favorite is EditPad Pro) is much faster in handling huge text documents; 2) there are other file formats and tools for the physical layout of text documents (e.g., LaTex and LyX respectively); 3) a word processor encourages its users to blur or totally forget the distinction between the logical structure and physical layout of text documents.
For the first reason I use my favorite text editor exclusively when the physical layout of a text document is irrelevant. But it has two limitations: 1) of course, it cannot format text; 2) it is not an efficient tool for dealing with long and complicated text documents like books (in this respect text editors are not better than word processors).
Rather recently I found a solution to the second problem - Scrivener, which I would define as an integrated writing environment. The user manual of this amazing tool descrives the problem it solves as follows:
Most word processors and text editors aimed at writers assume the creative process will take place in linear form; that is, they assume that the writer knows how his or her work will begin and will start at the beginning and continue through until reaching the end, and for those that do work that way, they assume that a linear form is a useful format for a text that spans hundreds of pages. Planning and restructuring is therefore forced into a separate workflow - the writer must either plan before beginning and keep track of hundreds of different files using the computer or face the laborious task of cutting and pasting numerous chunks of text to restructure a long piece of work at the end. For shorter pieces of writing, this is not a massive problem, but for longer texts - such as novels or academic theses - the writer can often find him- or herself battling against the tools of their trade. What a word processor does get right is in not presuming anything of your working methods. It is, at the core, ruthlessly simple.
I used to think that Scrivener was a WYSIWYG tool like a word processor. Actually, it is. But I have just found that it can also be used as a WYSIWYM tool, and that in a very convenient manner with a lightweight markup language called MultiMarkdown, which, unlike XML, does not get in the way of the actual process of writing, especially when one writes in an RTL script like Hebrew. Scrivener can convert structured text written with MultiMarkdown into a number of appropriate physical layout in various formats like plain text, ODT, Word, LaTeX, PDF, EPUB etc.
In conclusion, I would even say that at least as far as I am concerned, the switch from a word processor to this amazing integrated writing environment, especially after I have found its support for MultiMarkdown, is even more fundamental and revolutionary than the switch from a typewriter to a word processor. But it goes without saying that I have nothing against all kinds of "creative" uses of a word processor, especially Word, other than writing per se. ;-)