Google made this announcement today:
Starting this week, you may start seeing a new referring URL format for visitors coming from Google search result pages. Up to now, the usual referrer for clicks on search results for the term “flowers”, for example, would be something like this:
Now you will start seeing some referrer strings that look like this:
The key difference between these two urls is that instead of “/search?” the URL contains a “/url?”. If you run your own analyses, be sure that you do not depend on the “/search?” portion of the URL to determine if a visit started with an organic search click
…analytics packages may need to adapt to this change in our referrer string to maintain accurate reports.
Just thought I’d throw a heads-up out there.