As of press time, the federal government is still shut down.
This has affected most Mapping (TOPO) services maintained by the US Government except the critical maps needed to protect lives and property (USGS Announcement)
We can confirm that USGS Topo and USGS Color Aerials are currently down.
Other US mapping services (e.g. USForest2013, USTopo Imagery and the rest of the US maps) are working fine at the moment.
We will post further updates as soon as we get relevant news.