Indeed, there's a new ebook-production service (still in beta) named Vook which aims to give authors the ability to produce ebooks in all the major ebook formats, including EPUB, Amazon's formats, and now whatever Apple calls their new iBooks 2 format. An author would use Vook's software, not Apple's, so the iBooks Author EULA wouldn't apply. Smashwords offers a conversion service similar to Vook's, and is much older. (Disclosure: I have no association with Vook or Smashwords. I've just been researching the ebook industry recently.)
iBooks 2 format is more or less ePub3, as I understand it. I could understand it incorrectly.
I can also speak fairly highly of the leanpub team's process. My wife and I are finding it less than perfect for our needs in producing a fiction book with both ebook and print-ready book needs, but appreciate the directness and promptness with which both Scott & Peter have been responding to us when we are raising issues with what we're seeing.
Better yet, their conversion is free with no commitment to sell your book on leanpub required. I'd happily pay for what they're providing for free because it's so damned easy.