@chris_of_arabia http://codepen.io has an "Embed" button that let you copy the code and paste it directly into your post, I guess (not sure) you need to be logged in to see that button. Just change XHTML validation to "Basic security checking" here: http://b2evolution.net/man/back-office-reference/users/user-groups/editing-user-groups/

http://jsfiddle.net has an embed option that works right away as well.

Thanks @mgsolipa, since my original post, I've found a few things that will do the trick (open graph, oembed, iframely) on a post by post basis. I still think it would be nice to have a plugin to automate things though, I'll work with what I've got for now though.