I think it's only Idaho currently, but if it's true that most cyclists are adopting the "Idaho Stop" it's only a matter of time. Objectively, it may in fact be safer by virtue of spending less time in the intersection.

I can and have argued the other side, that it's better to come to a full stop every time because pedestrians have a right to expect the stop, and with that expectation will confidently walk out in front of a rider without any warning signs. You can't always see them, and they may assume you're stopping. It is after all the law. But that argument fails if rolling stop (or Idaho stop) is common and expected. And, of course, an emergency stop from 5 mph or even 10 mph doesn't put the pedestrian in that much danger.