It's not shutdown permanently. The U.S. federal government is on the brink of shutting down due to a political dispute. It won't likely last very long, so your trip is probably safe.
Edit - I should qualify that: there's no real way of knowing how long it will be shut down. These shutdowns don't happen all that frequently, but there was one during the Clinton administration that lasted 21 days. That's the longest, I believe. A contingency plan on your part might not hurt, depending on when your trip is scheduled for.
