I have seen personally that you can get a daughter to enjoy boy things but good luck getting a boy to participate and enjoy girly things.
But I wouldn't call Potter a boy thing. It bridges the gap; the smartest young wizard is female, and some of the most important characters are also female. Heck, Forbidden Journey starts with one of them casting a spell on you, the guests! The love stories help bridge the gap as well.
Disney made a smart move to put a 'thrill' ride in New Fantasyland, but I don't think a Snow White mine train is going to draw as many boys as they would hope. Their best bet is The Avengers, but alas that is doubtful for Florida.
/although I'm surprised that Disney hasn't played the 'The Avengers characters aren't the same as the ones you have rights to. You see Captain America? He looks nothing like yours. Thor? The same. The Hulk - again, not the same look. Black Widow, Hawkeye...etc.
"You don't have the rights to Joss Whedon's The Avengers; we do, so we can put them at WDW"
/if they are doing it, it won't be announced until right before groundbreaking or even as late as possible me thinks