However, from what we can tell after looking at cached versions of OpenLibrary.org, material has been available here for some time. Here's a cached page from Gigablast (2005) and The WayBack Machine from January 4, 2007. The page and content that's live today is the same as what we see with the cached versions of the site. In fact, some of the books were also added to The Wayback Archive in late 2006. Example.
Does it really matter? No. It's likely today what the official launch and the ars technica article is a worthy ready.
Of course, don't forget that MANY public libraries offer access to services like NetLibrary (full text NEW books) and ebrary. In fact, ebrary also offers a service with free full text access to over 20,000 books. You just pay to print a page or save it to your hard drive.
Postscript: How could we post about ebooks and note mention the following AMAZING resources:
The FreePint Family is a family of resources to help information workers be more effective, raise the value of information in their organisations and contribute to success.
'FreePint... provides most of my professional development because it won't come through work and [other resources] just don't cut it.'
FUMSI Forum: Do you have a research question? Post it to the FUMSI Forum, where professionals share Q&A and useful tips on how to Find, Use, Manage and Share Information. It's free.