For those of you who ue the PIWIK-data in their own Excel (or whatever) sheets and used to automagically import data via an API call it might be of interest that the call
/index.php?module=API&method=Referers.getRefererType&etc.pp.
has changed to
/index.php?module=API&method=Referrers.getReferrerType&etc.pp.
In the new wbesite layout, I couldn’t find the API documentation anymore, maybe it is already mentioned there.