Launch processing for MAVEN will continue despite the government shutdown:http://lasp.colorado.edu/home/maven/2013/10/03/maven-reactivation-status-update/
Sep 22 02:00: (approx.) MAVEN orbit insertion. MAVEN observations of the comet will only occur if orbit insertion goes off without a hitch. Although they will not be in their science mission yet, MAVEN has already acquired experience in attempting comet observations: they tried to study ISON. They didn't succeed in detecting it, but it gave them valuable practice for the Siding Spring campaign.
MAVEN had been considering delaying their transition from initial orbit into science orbit because that would have allowed them to hide behind Mars longer. MAVEN has decided to stick with their initial plan.