This is good news for libraries, but there's one important detail which tempers any excitement.
Hachette plans to sell the ebooks to libraries at a significant markup over the price of the print edition. The current plan is to release new ebooks at the same time as the print edition and price the ebook at three times the price of the physical book. One year after publication the price of the ebook will drop to only 1.5 times the primary book price.
According to the press release, the "primary book price will be defined as the highest-price edition then in print." That means that if Hachette considers the hardback to still be in print then the ebook will be priced at 50% above the retail price of the hardback.
Never mind that the consumer price for the hardback will actually be actually be in the $10 to $20 range; the year-old ebook will cost $45 (about). But at least the ebooks will be available.
Hachette is only the latest major US publisher to change their mind about selling ebooks to libraries. About 2 weeks ago Simon & Schuster announced a pilot program where they will sell ebooks to libraries on 1 year licenses. They are joined in their efforts to minimize library ebook sales by Random House, which significantly increased library ebook prices in 2012, and Macmillan, which is currently trialing a small pilot with 1200 backlist titles. HarperCollins, as you probably know, enacted a 26 checkout limit in 2011. And Penguin launched a pilot program last Fall to test a 1 year license and later expanded the pilot to include all libraries.