I believe the children that come out of homes with homosexual parents will be far wiser about the topic of homophobia then most adults are today. Homosexuality has been stigmatized for centuries and it will take many decades to get past this, however I do no think the children of these homes will have a hard time dealing with homophobia. They'll simply look down on people with homophobic tendencies.
A majority of people in the United States support gay marriage now, so incidents of societal homophobia will decrease as time moves forward and more generations become more liberal in their thinking. Some kids of homosexual couples may encounter bullying in schools, which is when schools must intervene and teach tolerance and love as family values.
In today's society children of gay parents will be okay growing up. I can't say they will never face prejudice or issues growing up but I do not think they are going to be in any more substansive danger than any other child growing up in the world. As time goes by it will lessen more and more.
In areas where homophobia is a problem, adopted children of
gays will have excellent help in dealing with it. Their adoptive parents will
have dealt with homophobia many times before. They will be ready and willing to
help their children deal with the thoughtless attacks of ignorant homophobes. Chances
are, the children will be straight, because most people are. They will grow up
without a trace of homophobia, though, and will help to create a more just
world for their children, and all children, straight or gay.
Yes, the children of gay parents will be able to deal with social homophobia, because Americans are largely tolerant. Americans are very kind, and are a lot nicer than people give them credit for. These children can educate others on the good qualities of having two concerned parents. Most gay couples have to go to great trouble to have children, so the children of these relationships are very loved.
There already are gay parents - with or without adoption. The children of gay parents have a support system that has already dealt with homophobia and can offer support and advice. These children are better prepared to deal with diversity in the world, and some may even be gay themselves. We don't discriminate against other minorities because other people don't like the religion they are, or because of skin color. It makes no sense to punish the one being bullied. Punish the bully!
With the many children of gay parents who are in school right now and with the acceptance for gay marriage being much wider than ever before, homophobia is held in check. Of course, the kids need to be taught to deal with any they encounter and to stay away from certain people who carry it.