Our WordPress network is back to running the latest version of WordPress core. Version 3.6 was released on August 1, so I waited at least a week for any major issues to crop up with WordPress itself with third-party plugins. Everything looks good so far.
Little blue flag windows will show up in the post and page editors to let you know about the new features. The revisions interface is completely redone and has a useful slider to explore the revision history. Autosave now saves a local copy in the client browser if a network connection cannot be established. The Add Media dialog has been slightly refined and now includes a built-in HTML5-based media player for embedded audio and video.
We would ask, though, that you continue to use external services for storing videos. The server has a limited capacity and would fill up quickly with video content.
Audio files are small enough to not be an issue. For audio, we have always used the Audio Player plugin. However, I experienced compatibility issues between the plugin-based player and the new WordPress-based player. I had to disable the plugin. The existing shortcodes that were inserted by the old player should be work fine with the new player. The main downside is that the old player was a bit more customizable. The new player should work great across all devices.
WordPress 3.6 audio player
One feature of 3.6 that is not yet activated across our network is the new Twenty Thirteen theme. I still have some work to do in order to create a “Princetonized” child theme of Twenty Thirteen.