I have some comments to post, stirred by the posts from thelionqueen and others. I will try to remain as unbiased as possible, although I have very strong opinions. We are at WDW all the time. We've often been at the world during gay week. Here is what we noticed last year.
There was one bill board along I-4 with the website and dates of gay week.
The crowd levels are affected at the designated park on the designated day. (You have that with any large group function at WDW.)
Some t-shirts worn by people were very questionable. There were equally questionable t-shirts protesting.
As for PDA, we did not notice any more PDA than usual. You have to remember that Disney attracts people from all over the world. (Hmm, I'm trying to word this carefully.) What's PDA for one culture is not PDA for another. (In some cultures it is customary to greet a friend with a kiss on the lips. Other cultures, girls link arms as they walk...and this doesn't mean it's a sign of affection.) This is a very common sight at WDW.
As for seeing gay couples at WDW, you really would have to be looking for it to see it. In all our years of going to WDW our son only noticed twice. Most couples, gay or straight do not seem to be all over each other at WDW.
As for explaining "things" to children: I'm always explaining things to my children. There are so many things in this world that go against my family's values. When my son sees something and asks about it, I explain what's going on and how I am either in agreement or in disagreement with it and why. Then he can form his own opinion.