On Kindle Nation Daily, here. Two interesting facts are that "Amazon said that in the past three months it has sold 143 Kindle books for every 100 hardcover copies sold, and no free ebooks were counted in that tabulation" and Bezos is quoted as saying, "We've reached a tipping point with the new price of Kindle--the growth rate of Kindle device unit sales has tripled since we lowered the price from $259 to $189."
Also, "of the 1.14 million ebooks sold through July 6 by author James Patterson, 867,881 were Kindle books. So Amazon has had a 76.1 percent market share of James Patterson's ebook sales." Moreover, "Amazon said that its overall ebook sales for the first half of 2010 were more than triple what they were in the first half of 2009."
In short, ebook and Kindle sales are exploding. It's a good time to be an indie author!