Adobe has enhanced its ePub support in various ways, not the least of which is that the output is far more likely to pass ePub validators, and thus more likely appear as you intended in an ePub reader. One reason is that InDesign CS6 supports the inclusion of your own CSS formatting files, which allows, for example, a reset to default settings of the reader’s device before rendering the ePub file.

Previewing your final ePub file is a hit-and-miss affair, so you’ll still want to preview it on as many devices as you can. Adobe's Digital Editions previewer still isn’t (and maybe can’t be) accurate in showing what an actual ePub reader will display. On the positive side, InDesign now exports .xhtml files instead of .html for compatibility with more readers.

Creating an ePub file is far easier in CS6 than it was before. For example, in the Paragraph Style options, the new Export Tagging category has a checkbox: Split Document (ePub only). When you export to ePub, you can use this feature to break pages based on paragraph style sheets (such as Section Head). This is so much easier than it was in CS5.5. The ePub Export Options dialog box has a smart redesign, with new support for custom bullets and numbers, and tables.

Other ePub-authoring improvements include allowing an inline frame to maintain its background color, frame width, and inset, and graphics anchored in the text flow can now be exported with their text wrap.