I've been making the claim of that headline for awhile now, and others are coming to the same conclusion. This is from a piece in The Scholarly Kitchen (a website dedicated to scholarly publishing) about the new gatekeepers...
If we were once concerned about the power of Gannett (who?), what are we to make of Amazon, which, depending on who’s counting, now has around 60% of the domestic ebooks market and between 20-30% of the print book market? When you get outside the trade publishing segment, those numbers move around. For some university presses Amazon’s share is around 50% of all books sold. Ebooks today are about 25% of all trade books sold, a number that reaches 60% for such segments as young adult fiction. Academic books today are still largely a print business (90%), but that is changing rapidly. As more and more books are consumed in digital form, Amazon’s overall market share for books will continue to rise.
And no one can stop them.
You can read the whole article here if you're interested. The piece also contains a pro-amazon point of view.
Late update: Here's another company Amazon is trying to crush: Overstock.com.