As of Nov. 9, 2011 Amazon added us-west-2 (US West Oregon) region: http://aws.typepad.com/aws/2011/11/now-open-us-west-portland-region.html

In looking at the EC2Snitch code (in the 0.8.x and 1.0.x branches), I see it determining which data center (which I think is supposed to be equivalent to region) it is in by this:

public Ec2Snitch() throws IOException, ConfigurationException
        // Split "us-east-1a" or "asia-1a" into "us-east"/"1a" and "asia"/"1a".
        String[] splits = awsApiCall(ZONE_NAME_QUERY_URL).split("-");
        ec2zone = splits[splits.length - 1];
        ec2region = splits.length < 3 ? splits[0] : splits[0] + "-" + splits[1];
        logger.info("EC2Snitch using region: " + ec2region + ", zone: " + ec2zone + ".");
The Ec2MultiRegionSnitch then has this reconnect logic - which I think the existence of a us-west-1 and us-west-2 regions and the way the Ec2Snitch is assigning data centers will cause this to break:

    private void reConnect(InetAddress endpoint, VersionedValue versionedValue)
        if (!getDatacenter(endpoint).equals(getDatacenter(public_ip)))
            return; // do nothing return back...
            InetAddress remoteIP = InetAddress.getByName(versionedValue.value);
            logger.debug(String.format("Intiated reconnect to an Internal IP %s for the %s", remoteIP, endpoint));
        } catch (UnknownHostException e)
            logger.error("Error in getting the IP address resolved: ", e);

Am I correct or do I not understand what was intended by these snitches?