Yes, but if I understand correctly, with the "embed video" button, it allows videos to be linked from multiple sources (Youtube, Yahoo Videos, Google Videos, Vimeo, Revver, Metacafe, Live Leak, MTV Videos and Daily Motion). When it is missing, I would be asking my blog authors to choose Youtube or Vimeo etc, which is not as streamlined.
Also, I'm still unclear why one of my sites has the "embed video" button available, and the other one doesn’t.