Print publishing, like film distribution or the music recording industry, has historically been licensed by territory – sometimes an individual country, but just as often for an entire region (say, South America), even if the region itself represents multiple written/spoken languages.
The Internet operates almost entirely non-territorially in terms of content distribution: this is the first, foremost, and most highly valued quality of the Internet[*].
Unfortunately, this has meant that for the entire history of the Internet, it has operated at cross-purposes with much of the commercial content distribution channels of the world. And it has only been very slowly, as they are dragged kicking and screaming epithets that would make a sailor blush, that these industries have come to the realization that the Internet isn't going away, and cannot be fully controlled.
To address the issue of eBooks specifically, it basically boils down to simple contract negotiation:
Most contracts for the vast majority of books in existence were signed before eBooks had any significant market presence, and as such rights for eBook distribution are largely governed on the publisher's – rather than the author's – preferred terms. Is this sounding a lot like the music industry again? There's a reason for that.
On the other hand, unlike music, which most people are happy to replay over and over, and perhaps even pay for a live event, books are typically read once or twice – and while some authors can command for-pay speaking engagements and appearances, most of the time they are "happy" to tour the country to do readings and signings for free[†] in the hopes that it helps sell another 10-20 copies per city.
So, really, it's a different business in which most authors working with a publisher never receive more than their initial advance against royalties, are generally happier the more involved the publisher is, and are also happy when the publishers place restrictions "in an effort to curb piracy/increase licensing revenues" using the outdated per-region model, since they don't really have another way to bring in cash – besides writing another book. Which is why so few authors don't also have a day/side job per capita compared to 'published' musicians/film directors/television actors/etc.
Anyway, all this boils down to the following: eBooks are a new phenomenon working within an old framework. As new contracts are written, things are (glacially) changing in favor of innovations like "per language" licensing terms for digital content – which is ultimately a benefit to readers in countries that may never get a native, say, Swedish edition of a book that is released in German/English/etc), the source publisher/author (fewer third parties to deal with/sign off on), and even the licensees of really obscure languages – who can now be the "sole world source of the Tamil edition", rather than having to battle it out with… Okay, nevermind. But for really any multi-country language that supports a large enough readership, it's a huge win and can't get here fast enough.
Amazon gets this, and they are totally on our side – much like the various states/localities that are implementing affiliate taxation, it makes things so much more complicated for Amazon that it's easier to pull out than adhere to rules made to prop up pre-Internet economies. They would be overjoyed to offer English language eBooks the world over, just like Apple would kill to be able to sell the J-Pop catalog available to iTunes customers in Japan to all the anime-obsessed otaku back here in the US.
Long story short: it'll happen. But, based on the current pacing, it's easily still a 20 year mission to get it to happen, barring more significant economic disruption (or even environmental concerns over dead-tree book production/distribution) than we have seen to date. Much like digital music, movies, and television, though, I think we'll need to see a greater uptick in either direct consumer demand for such licensing changes (led, or agreed to, by a robust conclave of notable authors), or eBook piracy[ª] that cuts deeply into legal publishers' revenues.
[* Not really, it's actually porn, of course. ]
[† Usually paid for at least in part by the publisher, and again stuffed somewhere in the contract under "author obligations". ]
[ª Due to the overall lower consumption of books compared to other media today, piracy still hasn't really flourished to the same extent – I can, at the snap of my fingers, download a torrent of the soundtrack to "The Best Little Whorehouse in Texas" in minutes, but even finding a listing for a tenth of the bestselling books available for Kindle/iBooks/Kobo/etc is a challenge well beyond me. ]