I just talked to my in-laws who live a little north of Hilo. They said there are no known fatalities, but a lot of minor property damage on the Big Island, as well as a landslide blocking part of the main highway and a few incidents of major structural damage. Their whole house shook and they said they felt several very strong aftershocks. Power is still out across large swathes of all the islands and the governor has declared a state of emergency, apparently because there are concerns that more areas of roads, especially bridges, will turn out to have been damaged enough to become unstable (on the Big Island only, I think). Initially as redhotswami mentioned there was some panic that a tsunami might result (Hilo has been destroyed by one before), but now they are saying nothing more than heightened wave activity.
I would imagine the airports are a mess at the moment.