"but as I far as I can remember
the embed tag is now out of the window? at least with XHTML? "
Tell that to YouTube and Google Video, two of the most popular video
sharing sites on the Web who still utilize EMBED tags (Google Video
extensively). :) I mean unless you can come up with an easy way to
convert video code with EMBED tags in it to OBJECT tags so that the
end user doesn't have to figure it out themselves (i.e. parameters,
etc) then I think you need to keep supporting outdated tags.