Google's rich snippets have evolved a lot of the years. They even released a new set of guidelines specifically named rich snippets guidelines.
To help webmasters understand rich snippets, implementation, and guidelines - Google's Pierre Far is hosting a Google+ Hangout Friday 1:30UK time, which is 8:30am EDT time for users to ask him questions live about it.
To find out about the event, go to Pierre's post on Google+, +1 it and he will invite you. You can submit questions beforehand, even if you can't make it, via Google Moderator. The hangout should be recorded for viewing later and I'll try to update this post with it after it is available.
Pierre said, "Hangout specifically to answer questions about rich snippets and the Google rich snippets guidelines."
Forum discussion at Google+.
Update: Here is the hangout:
