@sil - Yeah, that's how it works. You just have to use the action to cast it in a combat scene. Outside of a combat scenario cantrips can be perpetually used without much issue.
@sil - Characters with prestidigitation, druidcraft, or thaumaturgy get to really live up the whole "I am a creature of MAGIC, mortals!" thing thanks to those rules, which I really appreciate in a spotlight junkie drama queen sort of way.