From their page:
"AmazonEncore is a new program whereby Amazon will use information such as customer reviews on Amazon.com to identify exceptional, overlooked books and authors with more potential than their sales may indicate. Amazon will then partner with the authors to re-introduce their books to readers through marketing support and distribution into multiple channels and formats, such as the Amazon.com Books Store, Amazon Kindle Store, Audible.com, and national and independent bookstores via third-party wholesalers."
What does this mean? Amazon will pick self-published/small press books that garner many good reviews and re-brand them under the AmazonEncore banner? I can already see desperate wannabes out there already making plans to beg for and trade reviews on Amazon at an even more fevered pitch than before. What's the catch? Is there a fee to get into their program? I did a Google search and checked PW's website, but so far it seems that people don't know much about the program as well.
From their brief and not-very-informative homepage, I'd suspect that what would be of interest would be the "national and independent bookstores via third-party wholesalers" part. If Amazon can do what most small presses and vanity publishers can't - getting those books in bookstores all over America - that will be a pretty big breakthrough in itself.