Why is it traditional to use Latin in example pages? Is actual hypothetical content too confusing?
In http://whiffdoc.appspot.com/docs/W1100_1300.menus I snarfed chunks of text from wikipedia -- does this make the page more confusing than if I used Latin or Sanskrit?
The famous lorem ipsum dolor passage is not Latin at all. As explained by a site dedicated to the passage, it's actually quite historic:
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
As for an explanation of why:
It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).
+1 for allowing me to learn something new, I didn't know this. Cool.
"Lorem ipsum" pseudo-latin is also used as placeholder text, because 1) it is similar in format (consonant/vowel balance, word size, punctuation) to real text but 2) it has no meaning, so clients or others won't be distracted by reading actual words. Humans have a tendency to automatically read words that are put in front of them, but in an example page you want them to focus on the layout, functionality, etc.
To answer the question about your own site: yes, using wikipedia test could make it more confusing, or at least cause a potential user to think that the application was intended for a particular purpose ("sure, it works for factual entries, but I'm trying to write a novel").
I like 37 Signals take on Ipsum text, from Getting Real:
Insert actual text instead of lorem ipsum
Lorem ipsum dolor is a trusted friend of designers. Dummy text helps people get what the design will look like once it's fleshed out. But dummy text can be dangerous too.
Lorem ipsum changes the way copy is viewed. It reduces text-based content to a visual design element — a shape of text — instead of what it should be: valuable information someone is going to have to enter and/or read. Dummy text means you won't see the inevitable variations that show up once real information is entered. It means you won't know what it's like to fill out forms on your site. Dummy text is a veil between you and reality.
Just read "Getting Real" and they have some good arguments against using any kind of "filler" text in your prototypes/mockups. For example, when designing a user profile page resist the temptation to fill every part of the page with filler text because most commonly, new users won't fill in user details. They do a much better job explaining than I can, but for most cases it makes more sense to design a page around what it will look like without content.
They also argue (which I tend to agree with) that if you must fill the page with some sort of filler, take the time to write copy that is meaningful in the context of the application rather than using filler text.