Right now if I have a Word document or an entire PDF or Mobi-format book, I can email them both to my special Kindle address and, for 10¢ a pop, they will get converted to Kindle-format and sent to my Kindle the next time I turn on the wireless. Amazon plans to increase the minimum charge to 15¢ and to change by file size, which means the book could end up costing a lot more than the Word doc. Of course, I can still avoid the charges by emailing the files to a different address, which will then convert them for free and email them back to me. Once converted, I can then copy them to my Kindle using the USB cable that came with it, which I have used exactly once.
Amazon, do you not get it? Kindle and Sony both use the same e-ink screens. The best thing you've got going for you is the wireless! Maybe you think too many people are taking advantage of free ebooks and then emailing them to their Kindles, but so what? Are you trying to drive those folks into Sony's arms by making Sony and Kindle equal when it comes to free ebooks? And why did I, a Kindle owner, learn about this from Twitter and Gizmodo instead of from Amazon?
I see this move as a big “Doh!” on Amazon's part.
Addendum: This blog post suggests that Sprint is charging Amazon more, and they are just passing on the charges. If that's the case, Amazon needs to say so fast, and directly to Kindle customers instead of letting the blogosphere run amok with the news.
Addendum 2: It appears Amazon announced the change on the the Kindle blog, which I somehow did not know about. Not as good as an email, but at least it came from them.