Political Animals is, indeed, cancelled. So...
Sigourney Weaver - Starfleet Admiral
Carla Gugino - Romulan
James Wolk - Vorta
Sebastian Stan - Romulan spy pretending to be Vulcan
Ciaran Hinds - Klingon
Adrian Pasdar - aforementioned Cardassian
Dylan Baker - weasly Fed bureaucrat
Ellen Burstyn - Harry Mudd's ass-kicking space pirate momma
Scary how easy that was.