I believe TinyMCE has an "iFrame" button that allows you to drop in compatible embed code from any website that serves embeddable content. This solves the problem of forcing luddites to use the View HTML mode. Youtube is great, but there are a lot of other great sites (e.g. libraries, museums, universities, video collections, Tackk, bulbapp, etc..) that provide embed codes, but Canvas has no easy way of dropping that in the WYSIWYG. TinyMCE has the functionality for sure.