The Horrific Appearance ability for a Gorgoros states
Creatures that succumb to a Gorgoros’s horrific appearance find their eyes drawn to the creature’s gaze and must immediately attempt a saving throw against its gaze attack. Affected creatures can’t avert or close their eyes, and treat creatures other than the gorgoros as having concealment.
I'm here for the bolded text. How long do other creatures have concealment from someone who failed their save against this ability? Instinct tells me it lasts until the beginning of the Gorgoros's next turn.
Side note: these guys are SCARY! Gaze attack for permanent petrification, at which point, it can auto-kill a petrified creature as a Standard action. It gets a free attempt to petrify everyone within 30' every round. Then, it can make everyone save against petrification AGAIN as a Standard action, and if it has anyone grappled in its many tails (which it can also do as a Free action agaisnt any creature adjacent to it!), it can make them save against petrification a THIRD time as a Swift action. Vital Strike on a 4d6 Bite attack is nothing to sneeze at, either. Not to mention Freedom of Movement, SR/DR, and a 40' Earth Glide. Just gushing, here; I'm mostly interested in my above question :)
My original turnover included the text "This effect lasts for one minute."
...but since that got cut, I can only assume it wasn't intended to work that way.
No idea. My guess would have been "until you cannot see it any more", but yours is probably more fair.
This is what I would go with as well. ^_^