In addition to the ability to embed tweets I've implemented an enhanced embed for YouTube videos. Again very simple to use with the URL of the YouTube video you'd like to show in your posts:
Browse to the YouTube video you want to embed
Copy the URL from the browser navigation bar
In your post click on the button labelled "yt" and paste the URL
I've also added a second option to embed a YouTube video and start it at a specific time (expressed in seconds from the beginning). To use it, choose the "yt=" button option and enter the time in seconds from which you'd like the video to play after the "=" sign
Usage:
E.g. to start this video from the 2 minute mark (120 seconds)