danimalSK - 10:42 am on Jan 27, 2012 (gmt 0)
Was sent this screenshot by a colleague in the US (I'm UK based and can't recreate it here);
To do this Google must be building an index of concert dates (harder than you might imagine, because event meta data is often messy and hard to disambiguate). This is not just a form of rich snippets / sitelinks, it is showing data that doesn't even exist on the site.
This looks to me like the beginning of Google moving into another vertical.