Andy, the roadmap for ES 1.4 says "Videos for EasySocial" which is great, but does not indicate anything about embedding in walls. The good news is that while there is no embedding inside the stream, when putting in a YouTube link it generates a thumbnail that can be clicked making the video playable inside the stream.
If you want to truly be able to embed videos, your better off trying to convince the stacked team (and create a user voice page of course) of allowing HTML into the stream which will open up a lot of possibilities. Targeting bigger audiences beyond your needs that can accomplish what you want but help many other people who use ES is your strongest bet at getting something implemented (the most good for the greatest number of people). I often make request not specifically for what I want specifically, but instead go for something more universal.