Another great bit of analysis from the New York Times:
The deal struck with Apple also allowed other players into the e-book business, including independent bookstores. Previously, Amazon’s $9.99 subprofit price was a virtually impenetrable barrier to entry for anyone who couldn’t afford to lose millions in order to gain market share. Remember that it was only after agency pricing went into effect that Barnes & Noble was able to gain an impressive 27 percent of the e-book market.
Now Amazon has the Justice Department as an ally to rebuild its monopoly and wipe out other players. If the decision to charge the publishers was good for competition, why had the stock price of Barnes & Noble dropped more than 10 percent since Wednesday? Borders is long gone, and the possible loss of Barnes & Noble would be bad for consumer choice, online or off.
The whole article is worth a read.