"The relevant Wikepidia article includes a statement that ePub isn't very good for content that uses "fancier" layouts and fiddly bits of formatting. Presumably that means newspapers, magazines, comics, technical journals, computer books and so on are going to be really hard to crowbar into the ePub standard." and another poster stated that they doubt all those really require than degree of control in layout.
I don't think they do, either. I'll put down my reasons why, since I've been cruising through all those layout books in the last few months.
Newspapers and magazines have multi-column layouts in large part because a column that's narrower than their full pages is easier to read, in that it's easier for your eyes to jump over to the beginning of the next page. If you're engaged with reading the item for a while, like a hardback book, you can do a longer line. If you're skimming, or reading short bits, a shorter line works better. Plus, short newspaper paragraphs and stories would both look silly on a wide column, and with lots of short paragraphs, a narrower column is actually more efficient.
I learned that one for myself when doing the DucKon program book. If you have lots of short lines or paragraphs, you can get more information onto your page if you have multiple/narrower columns. The experts probably have guidelines for the optimum column width given this type size and that typical paragraph length and whatnot, but that's neither here nor there. Look at print fiction books - I suspect the usual size of a hardback evolved partly because that's about a maximum comfortable line length.
If you look at (older) newspapers and professional journals that have very few illustrations, they still use multiple columns. It isn't something that's done solely to allow incorporation of illustrations, etc.
Now, for items like PDAs, E-readers, netbooks, and such, the screen itself isn't very wide, so you get away from the need for multiple columns in order to get a comfortable line length. And even on wider-screen displays, like a larger laptop or big desktop monitor, you can re-size your window to give you a comfortable line length - I do this if I'm reading something from Gutenberg on my laptop or desktop.
One of the other reasons for fancier layouts is, of course, getting multiple headlines "above the fold" in newspaper parlance. On the initial screen without scrolling, in web-blather. With hypertext(-ish) links, you can get a similar effect by having a list of headlines possibly with snippets so that you can jump to the rest of the story you're interested in. An RSS feed of the BBC news page would be an example.
Adding illustrations in increases the complexity. If you have something like a newspaper or magazine article where the illustration is relevant to the article as a whole, but you don't need to have a relevant bit of text and the illustration in useful proximity, you can put the articles in-line, at a convenient place like a chapter,
section, or paragraph break - I've got several E-books, I think mostly in ePub format, that do exactly that, and I think it works pretty well. It's like non-fiction print books that put photos or other illustrations in one section for production-cost reasons.
I think a lot of it is going to be the layout and design people adjusting their thinking to work with the single-column paradigm. Things that don't seem to be amenable to it now, like newspapers and magazines, probably will evolve and adapt. I expect they already are, IIRC some papers have on-line versions optimized for mobile, ie: small-screen, browsers.
Where I agree that ePub, and probably most e-book formats, are weak are the things like computer books and other technical publications, and probably some textbooks, where you need this bit of text and this illustration, formula, or whatever, and you need to be able to look at both at the same time. That's tougher to do when you don't can't control screen/page breaks, etc.
I also find electronic publications less useful for things where I use them by flipping around or back and forth a lot, not reading from start to finish, even with linking. That's why I like software that comes with paper, not just electronic, manuals. (although that's kind of a lost fight) It's why I can see e-books working for some textbooks, but not others: an example being my son's math textbook, where he's going back and forth between the problems he's working and the examples.