Is it just me or is Google DNS not resolving .us domains?

Google's DNS servers (8.8.8.8, 8.8.4.4) seem to not be resolving .us domains. Is anyone else having this issue? If so, why is it happening? Google nslookup about.us 8.8.8.8 Server: 8.8.8.8 Address: 8.8.8.8#53 server can't find about.us: NXDOMAIN OpenDNS nslookup about.us 208.67.222.222 Server: 208.67.222.222 Address: 208.67.222.222#53 Non-authoritative answer: Name: about.us Address: 156.154.193.226 Name: about.us Address: 156.154.42.226