Microsoft has dropped out of the Open Content Alliance. I can't say I'm surprised, and not for the reason you think - since they (or more accurately, Gates) have gotten into philanthropy, they have a real point. Since they focus on global health, their considerable money is probably better spent there. After all, the dead can't read online books (or, the cynic in me says, buy MS products).
But in any case, they were gracious enough to leave their equipment and not lock up their content. Good for them!
What will this mean for the OCA? One less partner, less money, neither of which is good. Will it stop the OCA? I doubt it. There are too many well-endowed partners with too wide a base of support, plus considerable technical knowledge.
Will it ever be a rival to Google? Yes. It does have its niche, as does Project Gutenberg; they appeal to open source fans and people with slow connection rates, and they're serious about access. No silo here.
What is seriously threatened are the silos of online books - NetLibrary and its ilk. While Google may not make all public domain works available and only show snippets of copyrighted works, at least they're findable. What good is full text, if you don't know it's there?
Business models will not be the only thing to change in the next few years, merely the early victims. Libraries are in line, as are publishers. Who else? Who knows? Brave new world!