Watching the live F8 coverage, I had some vision about Facebook new Open Graph. I remember that part when FriendFeed CEO talked about his experience and the magic 5 (on average, a new user won't become active unless he/she find 5 friends using the same site). I thought at that moment: "Oh well, sound amazing. The Open Graph with all the new social plugins will be good". It's not really true.
Today, when I visited a site. I was stunned seeing a few (Facebook) friends of mine did some activities on that site. OMG. It's a really strange feeling!
I believe the Open Graph with all the new social plugins will be GREAT! The idea is just... brilliant. Except the issue about privacy: the Instant Personalization is opt-out (which means everybody has it turned on automatically, user must explicitly turn it off, more about opt-out). Many people complained about it and they are warning people to turn off in order to protect privacy but I think most of them will just leave it on because they don't read all those nerdy sites. And basically, most of 500 million people is... quite a lot! I'm having it on anyway, the personalize experiences are fun and useful, love it!