It would be nice to adopt children in need, however it is not realistic for every couple since circumstances varies from one family to the other but I do believe that if members of the church would have more children whether by birth or adoption we will save the lives of many kids that are born into abusive homes.
I agree that it is an individual decision. It is a decision that may become more popular now with Haitian kids being parentless. I think LDS are more open to adoption. I know a few families that have done so multiple times and are very happy they did.
My wife and I have brought it up but only to arrive to be inconclusive with our decision. I think its wonderful many people do this though; but no, its not a necessity. Some people cannot get over the thought of taking in another child that is not of their own.
I see no better way to gather the sheep than to adopt a non-member child and give him an equal and fair chance at accepting the gospel in this life. You're not just giving him or her a chance to live better off, you're giving him or her a chance at eternal life and eternal marriage.
Does it really matter whether they're members or not you know what am I saying? Poverty, need and hunger doesn't know religion and I think thats how we should see it when is time to adopt a child in need you know what am I saying?