Apple has released, fixing a few bugs and extending Pages to be able to export the EPUB format used by the iBookstore.  in Keynote include problems printing handouts with rule lines, the slide switcher, and automatically resizing some images while changing slide size. In addition, Keynote, Numbers, and Pages all receive a fix for a bug related to tables. The update is 63.44 MB, and is available via Software Update or directly from Apple's Support Downloads page.
But the far more interesting news is that Apple has added support for the standard EPUB file format for electronic books to Pages, so it's now possible to export an EPUB from Pages. The reason this is interesting is that despite the fuss about EPUB, the tools available to create EPUB have been extremely limited, falling into four basic categories:
WYSIWYG editing and EPUB export: Until the release of Pages 9.0.4, has essentially owned this category, because it was the only professional program in either the word processing or page layout space that could export reasonable EPUB files that were more than straight text. There are also several writing tools aimed at creative writers - notably  and  and the upcoming  - that can export to EPUB, though it appears on a quick glance that they are relatively limited in terms of stylistic capabilities, along with features essential for professional writers like change tracking and commenting.
WYSIWYG EPUB editors: The only Mac-compatible program I know of that claims to provide WYSIWYG editing of EPUB is, a cross-platform, open-source tool that works, but has some serious usability problems. If you have an EPUB that you wish to edit with WYSIWYG editing tools, try Sigil. Beware though, since in my experience, Sigil ignores an EPUB's existing table-of-contents file and creates its own, which is often sub-optimal.
XML-focused editors: These programs, such as Syncro Soft's, provide tools for working with EPUB at the code level. Creating an EPUB with an XML editor is like building a Web site with BBEdit; you get a lot of control, but you have to know exactly what you're doing, and minor mistakes can require debugging.
Conversion tools: There are oodles of tools that claim that they can convert files from a wide variety of formats into EPUB. Frankly, none that I've tested has done squat with the Word or PDF documents that we create for Take Control. I suspect they would work with very simple documents.
In her book "," our friend Liz Castro provides oodles of useful information about building EPUBs in both InDesign and Word (where you're really saving your file as HTML, and then manipulating the HTML file in a variety of tweaky ways to create an EPUB). Liz sells the book (as an EPUB-formatted ebook, natch) directly, or you can buy it in print through  or any of the usual suspects. Since it's the sort of book you'll need to reference frequently while working, you'll either want the print version or an iPad for the ebook version; the content isn't well suited to the small iPhone screen.
So where does Pages fall? I haven't had much time to play with its EPUB capabilities yet, but it looks like a serious contender in the WYSIWYG editing and EPUB export category. To be clear, Pages cannot open or import an EPUB file, so it's useful only for exporting in EPUB format. (Luckily, Pages can import Word files quite well, so you may not be entirely out of luck if your documents are in Word format.)
Apple has published a has examined the template, and is generally positive about what Apple has done, identifying only one notable problem in the XHTML output. on the topic that offers an overview of EPUB and PDF, and how to create an EPUB file with Pages. Although you can create an EPUB simply by exporting any existing Pages document, the results may not be ideal unless you start from  that Apple makes available on the Web (it's not included with Pages 9.0.4, oddly). The sample document can be used as a template or you can copy its styles into your document. Liza Daly, one of the world's EPUB experts,
As a quick test, I imported the Word manuscript of Tonya's "" ebook into Pages, and immediately exported it as an EPUB. Almost shockingly, it was pretty darn good on the iPad. A number of internal navigation links were lost on import, but Pages retained the look and feel of our design, properly recognized the table of contents, dealt properly with Web links, and had no trouble with graphics. And when I ran the file through the  that Liza Daly's Threepress Consulting makes available, it passed with no errors.
With this new EPUB export added to all the commenting and change tracking features that have appeared in recent versions, Pages may now rank as real competition for Microsoft Word for serious writing. Of course, with Office 2011 due out in a few months, Microsoft has a chance to up the ante, but Apple can't be far from releasing a major update to iWork as well.