This weekend, Google was caught testing at least three different user interface designs within the search results. They tried bigger URLs listed under the search snippet, they tested a new navigation path to the cache and similar links within each search result and they are testing showing the number or quantity of products display on a particular page within the search results.
Let me show you each test.
(1) Bigger URLs under the search snippet was discovered by @jsilton:
If this is legit, hard to say. It might be something wrong with the browser settings or it may be a real Google test.
(2) Cache & Similar links moved as a drop down option within the search results was discovered by VITEB on Google+:
Interesting that they would call out that feature so much with an arrow down option. Don't you think?
(3) Google showing the number of products listed on a page as a rich snippet like snippet add on was discovered by Matt Storms on Google+:
I am not sure if this is a PLA feature or if it is rich snippet related, I cannot reproduce it.
As you can see, Google is constantly testing new user interfaces within the search results.
Forum discussion at Twitter, Google+ and Google+ respectively.