Just watched the f8 keynote. And came across this summary from Mike Postma that you might find useful.
- Open Graph will link all those different social graphs together making the Internet more social and personalized, smarter and more semantically aware. - For example, Pandora (an American-based online radio) will immediately play songs from bands that you’ve liked across the web. While you play music, the site will show you friends who also like the song, and you can click to see what else they like. I can see a similar integration with YouTube reduce the world’s productivity by at least 40%. - The cool thing about this new Like button is that it is part of a much larger set of interconnected social plugins. For instance, the new Activity Stream plugin, which offers you an easy way of displaying relevant Facebook news feed items from other people on your own website. As a result, a first time visitor who’s completely unfamiliar with your website can immediately see that four of their friends visited your website before and liked several of your articles. This will instantly create a certain amount of trust and give the user extra initiative to explore your website, thus greatly improving website interaction. Other features that are worth Googling are “Recommendations”, a new “Sign in With Facebook” button and the Social Bar — Facebook’s “all in one social experience” that lives at the bottom of your website.Another summary here
Read the whole thing here
And everything you need to know about the changes according to facebook here
Mashable about the Open Graph here
Watch breakout sessions here