Allow posting of video from standard URL (not embed code)

I just noticed that the VideoSift Bookmarklet allows you to automagically create a posting from some of the popular video sites (YouTube, Vimeo, College Humor, Funny or Die, Daily Motion) and I wonder why is this same functionality not added to the standard submission page?

I wouldn't mind if it was an undocumented feature, have the validate button see if its a standard URL then check if its a supported site and form the embed just like the bookmarlet does.

This is VideoSift bookmarklet page http://videosift.com/bookmarklet/install