It won't make any difference. Most gays have never really experienced discrimination and only really begin to understand when they come out or are in the middle of something that comes up against their orientation like wanting to marry. And so a lot of gays know the discrimination is there and there is a risk it will affect them but until it actually does they only have an opinion about things like Rick Warren from a perspective of theory.
Most straight white middle class people have this same perspective and are in a majority and so a selection of Mr Warren is seen as maybe not as bad as it really is, and it is really bad. The reason I think that it really doesn't make any difference is because the opinion of the majority of people in this country towards gay people is already set and one more reinforcement won't even have an effect. Rick Warren is Not going to change his views and most all Americans won't change theirs either. We are only going to achieve a minimal amount of equal rights changes but the change of attitude towards gay people is only going to come through a change of generations, maybe two or three more at the least and so we won't see it in our lifetimes.
"Trust in the Lord with all my heart; and lean not unto my own understanding; In all my ways ackowledge him and he shall direct my paths" Proverbs 3, vs 5/6