Epub 3.1 was released several months ago: that included bug fixes, and ISO wording + backwards compatibility. IDPF is now thinking of the next version, and this was presented, by Markus Gylling, at a recent EDUPUB Symposium in Phoenix.
Various features to be added were mentioned like 3D format, migration of epub:type to the role attribute, or to HTML5. Some features may also be deprecated, like switch. However, at present, all those are just discussion items, no formal decisions or timeline yet; instead, a discussion among IDPF members should take place.
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