I have just seen that the British Library in London has reached a deal with Google to digitize roughly 250,000 books, newspapers, articles, etc from between 1700 and 1870. These years were chosen based on copyright. 1870 is the latest sure date that the European copyrights have expired. The British Library has the largest collection of books of any library in Great Britain and is the equivalent of our Library of Congress in that they automatically receive a copy of every single book published in the country.
Many of the books which will be digitized are currently not available in the public rooms of the library. Either they are too old or there is simply not enough room in the public areas of the library. Digitizing the books should give access to the books to everyone and make it easier to find historic information from them.
I, for one, am quite excited about the idea. Since the books will be available for free online, it means us historians from abroad can easily access the books without having to fly to London to do so.