It's right there on about.com's start page, a page I never personally knew existed. It's a discussion of Best Musicals that "won by default." I wonder if that's a fair assessment and what you guys think of the article? this way to the expert
They claim the Tony Winner for Best Book, James Joyce's The Dead, wasn't a good book musical. They claim Memphis was ambitious because it was about interracial romance. They also claim Applause won because of Lauran Bacall's star wattage. I gave up after that.
Full disclosure, I've only seen two of the shows (and one of those was the national tour) and none of the shows that competed against them. I guess there still are some racially stratified places where an interracial romance would seem unusual.