Shelfari is
tightening up its Amazon integration. If you already have a Shelfari account, you'll be asked if you want to link it with your Amazon account, and new users will log in with their Amazon credentials.
Shelfari has also made it easier to input books and ebooks purchased from Amazon. It's not automatic, but you can bring up a list of Amazon purchases and check them to import into your Shelfari library.
I know there are some who will think this is More Amazon Evil, since Shelfari is owned by Amazon, but for me, it makes Shelfari more useful by making it easier to add new books. As long as it isn't mandatory and you can choose which books to import, I think this is a big improvement for Shelfari.