Google recently announced that they will be making some changes to their referral string format which will be rolling out this week.

The old url referral string looked something like this:

The new one will look something like this:

There seems to be a lot more data in the new URL string but one of the main improvements that has been correctly guessed by Mr. Patrick Altoft at Blogstorm is that the new referral sting will have ranking and referral data embedded:

cd=7 (click detail = 7th) is the ranking and ct=res (click through = results) is indicating that the click came from organic search rather than a universal search (news or video) result.

If you're using Google Analytics then you don't need to worry about changing anything.  Google Analytics will not be affected by these changes.  However, if you are running Urchin or any other type of analytics package you should look into how to adjust your settings to account for this change otherwise your data might not be accurate.  More info on how to adjust here.  As far as tracking rankings, it seems like the easiest way to do that at this point would be to set up a filter in Google Analytics to capture the new referal strings. We'll keep you posted if anything new develops as far as that goes.

Edit: There have been a few posts recently that go over how to set up a filter in Google Analytics to see the rankings in your keywords report.  Here is one of the posts that shows you how to set up the filters in Google Analytics properly.