The Department of Justice has reached a settlement with three of the Big Six publishers to refrain from agency pricing for two years. (The three are HarperCollins, Hachette, and Simon and Schuster. Two others, Penguin and Macmillan, will take the fight to court. The sixth, Randomhouse, was not charged.)
Retailers (such as Amazon.com and BN.com) in their turn, may now discount individual titles to their hearts’ content–but may not make a loss on selling ebooks as a whole.
This could be bad new for midlist writers. Sadly I think what’s very likely to happen is that online retailers will engage in discounting price wars over bestsellers. All those brand new, hot buzzy books that currently sell for $14.99 book will become loss leaders, priced at $9.99. Or less. But midlist writers, whose books have been out for a year or two, will still be priced at $11.99. Or more. Sales of midlist novels–such as they are–will shift in farther in favour of new bestsellers. (Then of course there will have to be a recalibration in pricing, because online retailers won’t be allowed to take a loss.)
I have only one novel with one of the settling parties: The Blue Place. It’s currently priced at $9.99. So is Stay (with Randomhouse). My other novels range from $11.99 for Ammonite and Slow River, to $13.99 for Always. If the prices stay there, sales with wither…
…unless I’m horribly wrong about all this. I would love to be wrong. Thrilled, in fact.
Nicola Griffith 
In my experience – 12 years in retail bookselling in Atlanta – frontlist and midlist readers are two different breeds. If someone wants to read a Nicola Griffith novel, they're probably not going to settle for the newest Patricia Cornwell just because she's a couple bucks less.
In related news: I just loaned The Blue Place and Slow River to a coworker. Hopefully when she's finished with those, she'll go out and buy the rest…
I don't have the data w/ regard to long-term ebook buying, but my sense is a lot of discovering is influenced by price: why bother even reading the sample chapter when the product is $12.99? When the prices on my books went up, the sales went down. But I don't know what the numbers look like for other writers.