The Open Graph Protocol is a new methodology for storing metadata to make it easier for third party sites (think the Facebook LIKE button) to identify relevant content on yo
As far as I know, you're stuck - but if you figure out a way, let me know!
I worked on a project that needed to have multiple Open Graph tags on a page - in the end, we ended up trimming down the number of items we needed OG for, so that we'd only have one story on a page.