Cool, that means it'll appear in ebook reading systems in five to ten years.
It'll be in PDF sooner, and my experience is that PDF >> any other system for ebooks. I liked the idea of EPUB but when I recently installed an EPUB reader to read some files I was shocked at how awful it looked whereas for 15 years I've been reading PDF files on tablets with relish.
Only benefit is browsers have built-in support for the format.