Yeah, it is. Unfortunately, it requires you to post the file to the Scratch website first, then use the "link to this project" tab on the right of the project's page. Embed as an applet (not an image, this just creates a thumbnail that links to the project), then put the HTML into your own webpage.

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Embedding Scratch projects involves copying the Applet and sound file to your site, and inserting an Applet HTML tag into your webpage. You can find instructions at this forum thread:
http://scratch.mit.edu/forums/viewtopic.php?id=191&p=1
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