I read a wonderful inspiring story called 'A Child Called X' a few years ago, which seems to be what these people are trying to do. In the story the child is tested and found to be the most physchologically normal and well balanced in the school. Unfortunately, that is a STORY! I just don't see it happening in real life.
I think it is important not to force children to like something because we think it is what they should like, but a very good example of the psychological make-up of boys is found in my son. I refused to buy him anything transport based as a toy, barring a traditional train set and a clicking car track. I did this because I felt that there is too much focus on transport as the only thing boys can be interested in. I bought lots of animals and dinosaurs and traditional gender-neutral toys, like blocks and instruments and a kitchen.
But despite this, he has become as transport-obsessed as the next boy. And now that he's showing an interest, I am more than happy to buy him cars, or whatever he chooses. In fact, I bought him two cars today

I think it is great to let the child lead the interest, and not to force gender lines (I wouldn't object if my son wanted to take ballet, for example) but forcing a child to be genderless... I can't see it doing any good. Maybe they'll proove us all wrong!