I must say I was a little miffed when, in my opinion facebook decided to zig when the major search engines were talking about zagging in harmony using meta data or a particular schema of RDFa tags.
Both Facebooks Open Graph and Schema.org in basic terms are similar in that they are an extention of Resource Description Framework (RDF) > Resource Description Framework – in – attributes (RDFa)
The importance of this perhaps can be found here.
Now when you do a web search on Facebook, the new search results page features a two-column layout with Bing-powered web results appearing on the left-hand side overlaid with social information from Facebook including how many people like a given result. On the right hand side, you will see content from Facebook Pages and apps that are related to your search.
After all the build-up to Facebook's event at its Californian headquarters, Mark Zuckerberg's announcement left me - and I suspect millions of its users - distinctly underwhelmed. A new way of mining the information your friends, and their friends, post on the social network does not sound revolutionary.
And its geeky name Graph Search isn't going to win any marketing awards - Facebook's boffins may be in love with the idea of their social graph, but to many people it will sound about as exciting as double maths on a Friday afternoon.
And here is more info on Schema.org
More on Open Graph
PS as Tony has tried to tell folks repeatedly, Keyword meta tags are dead. sort of the cyber stone age