tedster - 3:59 am on Feb 25, 2012 (gmt 0)

I was just getting ready to post about this article and you beat me to it ;) - well done. The article ends with a confirmation that rich snippet data is involved:

If you have a website listing upcoming events and would like them to appear in search, you should add rich snippets markup to your web pages. After following the instructions to mark up your events, use the rich snippets testing tool to test your markup and see how it would appear on Google. This is currently available to those searching on google.com in English, and we'll continue to expand the feature to more countries in the future.