Well, I'm willing to be corrected, but there's a little hijinkery going on here. I'm talking about the news today of e-books out selling hardbacks at the Amazon store. Yes, expect to have the "Publishing is Dead, All Hail the New Format" folks doing happy dances all over the internets. Unfortunately, the news isn't all that good. First of all, this is just Amazon (and while Amazon is big, it's not that big). Next, it's just hardbacks, and if you read the whole thing, paperbacks are still the biggest sellers. Thirdly, for the past three years Amazon has had the Kindle at the top of it's home page. Also, there is no breakdown of if the books sold were new releases, or the $0.99 books. Or even the free ones offered by some self publishers.
As a secondary note, please see the whole, "When the iPad came out, Amazon slashed Kindle prices, which increased sales." Amazon also offers free Kindle readers for the iPhone and iPad. However, they aren't releasing numbers for their Kindle sales.
So good news for e-books. But not the world shattering news they want you to believe it is.
edited 7-20- 2:30pm Speaking of Amazon, here's an interesting look at the e-book kerfluffle of this past year. Not so good for the Amazon side. Warning, it's a long article (heck, I haven't finished it yet, but then I'm at work). The arguments about choice and "perspective" though are very informative. Also, lots of publishing as a business napery. Very good article.