Krazykiwi has all the info and links in this post here. Sounds like this is pretty much what Amazon has been doing in the past - alerting authors to mistakes - but this time there might be a little more push to get them to fix it. Of course with the huge amount of spelling/grammar fun that's out there, that's a ridiculously large job, so I wouldn't think there'd be any significant difference in quality for some time (if ever).
Fun part for me - I had no idea Amazon specifically defines "disappointing content," and was amused. Read the following and ponder how broad some of these statements are as far as what can be considered disappointing. (Some I'd rate much higher than the word disappoint and more towards "rarrrr inducing.")
Guide to Kindle Quality (scroll to end):
We do not allow content that disappoints our customers, including but not limited to:
• Content that is either marketed as a subscription or redirects readers to an external source to obtain the full content
• Content that is freely available on the web (unless you are the copyright owner of that content or the content is in the public domain). For more information, you can refer to the sections titled “Illegal and Infringing Content” and “Public Domain and Other Non-Exclusive Content” in the Content Guidelines.
• Content whose primary purpose is to solicit or advertise
• Content that is not significantly differentiated from another book available in the Kindle Store
• Content that is a non-differentiated version of another book available in the Kindle Store
• Content that is too short
• Content that is poorly translated
• Content that does not provide an enjoyable reading experience
Apparently all this time I could have been complaining about all those people selling public domain works with little change from the free online ebook versions. Did not know that. Though I might have had to purchase one and return it to be able to send that message - not sure.
They repeat the idea over here:
Poor Customer Experience
We don't accept books that provide a poor customer experience. We reserve the right to determine whether content provides a poor customer experience. See the Guide to Kindle Content Quality for examples of content that's typically disappointing to customers.
Anyway it's great to have these sorts of standards, but as usual the real problem is making sure the sellers follow them. I'm specifically thinking about having enough staff to manage all that content review and communication in a way that doesn't take years to fix each issue - because as we all know, it's usually always an issue that companies never seem to hire enough staff to do all the work.