I was kidding about the overrated bit.
What you could do is to change the default video image to something that is more styled to your theme with maybe "no thumbnail included" across it.
Where are you hosting the clipshare clips? Are they on your webserver?
The video plugin is for the viewing of online videos hosted elsewhere. I don't think there is currently a way of easily uploading a video to the site for it to be viewed.
The simplest solution would be to upload the files to youtube then use their embed code.
You could try and research
http://stackoverflow.com/questions/1732196/java-script-ajax-video-player-not-work-in-php-file but it means having to create a html code for each video. Not really easy.
I think users have been asking for a video upload ability but I am not aware of the progress (if any) on this...
Youtube is the quickest answer.