This is a great question, Cathy!
While the value of having video in email campaigns is high, there is the problem that many email clients like Gmail, Yahoo, and Outlook can't display embedded video. I'm sure the developers are eagerly awaiting a standard to be developed so they can implement this consistently!
While we wait for the tech world to agree on a standard, there are some options available to you! I would suggest using a static image that looks like a video – this will encourage high Click Through Rates! Even just including the word "video" in the subject line improves open rates!
It might not have the flash of embedded videos in email, but it does ensure everyone is getting the same message.