About the only thing I can think of to add to this plug-in would be an admin side addition. One that allows the admin to choose which type of media can be uploaded, therefore deciding which media upload buttons show up above the post section.
Using this on my site and I only allow image uploads, but I know some people will eventually try uploading other types of media. I have severely limited the amount of upload size but I would like to stop that practice before it starts, and this is the best way to do it.
Thanks for the cool plug-in.