I am happy to inform you that we have recently started supporting
oEmbed on SlideShare (http://www.slideshare.net) - the world's largest
community for sharing presentations online.
URL scheme: http://www.slideshare.net/*/*
API endpoint: http://www.slideshare.net/api/oembed/1
Supports discovery via <link> tags
Format: json, xml, jsonp
Example: http://www.slideshare.net/api/oembed/1?url=http://www.slideshare.net/haraldf/business-quotes-for-2011&format=json
Cool! And I'm very happy to see things using the 'rich' data type -- oEmbed ain't just for photos and video.
One minor problem; the thumbnail URL on the example is returned with a Content-Type of text/plain though it seems to be a JPEG file: http://cdn.slidesharecdn.com/110103quotes2010-12-110103073149-phpapp01-thumbnail
This causes Firefox to offer it as a download rather than showing the image, at least on a direct load.