Check out the Coming Out thread. I think, the reactions depend on a number of things.
First, the region you live in. How accepting are people generally? How is gay marriage treated? (I personally find it to be a good litmus test.) How prevalent is the One True Way To God And Heaven?
Also, how are you coming out to people? Do you come across as feeling shame, or like it's a secret? Or, are you acting more like it's just another fact about your relationship, like, you go out to the movies every Tuesday, and you like to cook together?
Those have been the biggest factors of influence that I've found. And of course, when it comes to family, throw everything out the window and hope for the best.