Setting global embed/oembed in WP 3.5

So I'm really impressed with WordPress 3.5. The new media uploader/manager is awesome and most of the other tweaks and such are great. However, I'm running into one problem: now that the embeds setting has been removed from Settings>Media how are we to set the width of embeds/oembeds? Look at the video at the bottom of this post. that doesn't look good! It should be the same width as the body paragraph. Yet, I don't want to have to insert embed code in each post that contains a video. One of many features I love is that you can just paste in the video URL and it takes care of the rest. But now that I can't set a width under the media settings the videos are too narrow. Has anyone come across a fix for this? Or was there something intended to replace it? I'm just not understanding why it's gone.