First let me point you to Jay Lake's thoughtful and thorough series of responses to the whole thing. That'll give you a good background. Here's John Scalzi's take on who failed the worst (hilarious, except for the billions of responses - though some of those are inadvertently hilarious, too). And today SFWA responds (that's the SF and Fantasy Writers of America).
My take? Unfortunately, nobody comes out of this smelling rosy. Macmillan is afraid of what ebook sales will do to their first-release print books, so they want to charge more for new releases and less for older ones. Amazon wants to discount all ebooks to sell more Kindles. Fair enough. But they decided to stab the hell out of each other behind the scenes rather than negotiate, with Amazon suddenly and unannouncedly pulling all (not just ebook) Macmillan titles from their store.
Screw the corporations, I say. I mean, geez, ever heard of negotiating a fair settlement for everyone? Ever heard of keeping the customer happy? I feel sorry for the authors whose titles will appear to do poorly on sales sheets because of this, which might kill careers, or at least kill deals on their next books. I feel sorry for the fans who don't know the full story and who might become embittered toward the whole publishing industry.
Today I noticed that Amazon is still not selling new Tor books (an imprint of Macmillan). Seriously? How's that helping you out, Amazon execs? Just for the record, here's a link to Powell's Books SF/F section. Bookmark it when you need to get a book that's not on Amazon! Powell's is one of the awesomest bookstores ever, an independent bookstore in Portland, Oregon, that fills a whole city block with more than a million new, used, and out-of-print books all shelved together. Shop those shelves — plus literally millions more books, DVDs, and eBooks — at Powells.com.
EDIT: Macmillan's CEO responds about the fracas. Thanks to gwyndolin for the tip.