I was able to answer my own question. Yes, there is a (fairly) simple way to embed Tableau into Axure prototypes.
1) Publish your sheet or dashboard to Tableau Online. You can test this functionality by using one of Tableau's public projects, like this one: http://www.tableau.com/stories/gallery/sales-and-opportunities
2) Once there, click share to copy the embed code. It will be the HTML code for a <div>
4) This file needs to be saved in the same folder as the HTML prototype generated in Axure. If you click Publish > HTML file, you'll see the filepath for the HTML file. If you've yet to generate an HTML file, do that now (otherwise the files won't exist). Name it (e.g. tableau-embed.html) and drop your newly created file into that folder.
5) On the Axure canvas, add an "inline frame" object. Double click on the inline frame to open the link properties dialog. Select "Link to an external URL or file." Type your HTML filename (e.g. tableau-embed.html) into the hyperlink field.
6. Be sure to fully generate the HTML prototype again to adopt the inline frame and hyperlink.
Happy to help with questions.