Has anyone else with servers outside the US noticed their SERPs vary dramatically from US datacentre and international ones?

Since the update of last week, my international datacentre SERPs are doing fine, but my US datacentre results have dropped off the planet.

I have read discussions about different algos for diff countries, but I wonder, is it at all possible that there may be a national bias at play (ie. non-US sites don't get the same points on the US datacenter)?