Is there a way to show an image of a youtube video instead of the actual player ? This would be done only for the teaser view of the node.
I know that I can show a video thumbnail, but I need an image that looks like the actual player.
If you can grab the id of youtube video then you can use following pattern of url to get a bigger youtube thumbnail.
http://img.youtube.com/vi/[your video id]/0.jpg
This would require a little work on your behalf to write a small module to get the youtube thumbnail and then process it.
For example if you use Embedded Media Field with Media: Youtube then you can get the URL with
$node->field_emvideo['data']['thumbnail']['url'] (*field_emvideo* is the name of your field) and use it with ImageCache Actions to add a background image which would be the Youtube player.
I don't have a full code to offer but using ImageCache API (see the code snippet at the bottom) is quite simple, ex:
<?php print theme('imagecache', $preset, $image['filepath'], $alt, $title, $attributes); ?>
Good luck ;)