There are celebrities that are almost certainly gay, but there is still that huge "cone of silence" that permeates the whole scene. Not to mention that some of the gay celebrities are in Scientology, and they frown upon homosexuality, so they won't be coming out any time soon.
Jodie Foster wasn't really a surpise, but Jim Nabors was. Of course, he didn't run around publicly saying "Lookie, lookie! Here I am, I'm gay! He, along with fellow actor George Takai, quietly remained in a long-term relationship with their partners.
It's definitely more acceptable in the entertainment industry, but not as much as it should be. The same with sports. How many athletes have come out (willingly, that is)? A few have, but usually they wait until they retire.