Hi All,
It looks like Google has setup a nice dev site and FAQ page to go over the options here especially when using AJAX and hash tags to link to hidden content. https://developers.google.com/webmasters/ajax-crawling/docs/faq#whereinresults.
It looks as if Google will be able to index the content of the entire page (hidden and initially shown) and not create a separate URL if you use a ! before the #. I'd read up on that FAQ page, and play with site commands on the Google dev site.