You might be right in abstract but in the real world technical decisions are often made by choosing the lesser of several evils.

Pure text is not good enough for many kinds of books - you need to at least support images (for cookbooks, children books, travel guides etc.), monospaced, bold, italic fonts (for programming books), vector graphics (for illustrations in technical books that will good at every dpi) etc.

There's no strictly ebook format that gives you that so you can either spend engineering resources trying to define and implement a new, non-trivial ebook format from scratch, with non-insignificant possibility of getting something wrong.

Or you can re-use the most wide spread document format in existence. A format that gives you everything you might ever want, has evolved over more than a decade, is tried and tested and works and is implemented on every platform imaginable and has open-source implementation that everyone can re-use.

HTML5 is the lesser of any other evil you can come up with as a new format for ebooks. Amazon made the right decision.

Wait, doesn't PDF support all of the above? Why require HTML rendering? All sorts of issues arise since HTML is markup based and not layout based like PDF or ePub...

As far as I know, PDFs don't reflow text. They're only suitable for a fixed screen size.

There's reflowable PDF but when there are things like illustrations and tables, it gets really ugly and really useless really fast.

Have you tried reading a PDF on a kindle? It works. technically. But it's not pleasant.

Being in the Kindle conversion and formatting business, one of the advantages of having such a simple format was that self-published authors can create books that look just like those from major publishing houses. There's only so much you can do to make something fancy with the current Kindle format. With more capabilities, we'll likely see people try and do 'fancy' and end up with stuff that's actually not that great looking.

The wording of the text regarding 'older readers' is also a bit confusing. Will material created for KF8 be 'automatically translated'? Will the tools output two different formats? I'm curious to see the details.

I guess I'll need to order a Fire though, in order to keep up... I was a bit ambivalent, as I'm not wild about not having the Google stuff, and about the Android fork of an older version.

The good stuff: table support currently sucks, and the ability to do a bit more with the formatting will help with things like manuals or textbooks, that currently don't always work well on the Kindle.

I am worried, though, that for many people, it will be "enough rope to hang themselves with".

If all you need to code is traditional novels, then what we already have is fine.

If you want to code poetry, plays, research with footnotes, or anything else, then having access to more options is a wish come true. (Waste a few hours trying to hack any of the above into epub and you'll feel my pain.)

It's not like making this available makes it harder to code novels at all, so why complain?

Overall, I agree. The thing I like most about my e-ink nook is that the only thing it can do is reading, as opposed to the iPad, which always has the temptation to play a game, or check the web, or chase that ding which means new mail.

That said, I think that HTML5 capabilities can improve the reading experience if used properly. iPad-type tablets can get access to interactive experiences with technical books and comics, kindle-type tablets get improved typography and layout. Some publishers may abuse the tech, but there's still a very strong market for Just Plain Reading, so I don't think it will be too bad.

Well, the devices, future and present, want to do a lot of things that traditional typesetting can’t do. Having known page and type sizes is an assumption of print, but goes out the window when one wants to put a piece of content on different devices.

But I absolutely agree that the book is a valuable, time-tested format. We’ve learned a lot about readability. Conflating the goals of books and web pages would be a loss. NB, we still have radio.

I think this is motivated more by Kindle Fire as a media consumption device than their e-ink readers. They make a compelling case with childrens books and comic books.

What about children books. What about innovative story telling formats. Magazines; old-school wired magazine could really do a number on kindle.

Yes, this is definitely needed. I have a book in an interlinear format that requires css floating elements for fluid display.

What is a book? Your kids will have a completely different notion of that than you...

At the moment I am still buying books for my son, and clumsy attempts at mimicking interactivity in paper based children's books seem to be all the rage. So even now books don't confine themselves to being just books.

Look at the many newspaper and magazine apps on the iPad. They often contain interactive content - videos, graphs you can blow up, slide shows, and so on. And I'd say they're better for that. If the Kindle Fire is going to compete with the iPad for those formats, it needs to provide a similar experience.