What about "Walk the Line?" Johnny Cash was a devout Christian as well as a tough SOB. And while Truman Capote was definately a homosexual, the movie isn't about that element of his life...it's not like he tried to hide it too hard.
I don't think Heath Ledger should beat out Joachin Phoenix or Phillip Seymour Hoffman for Best Actor, nor do I think the movie was better than the previously mentioned flics (nor was it better than "A History of Violence") But, since Terrence Malik is hated by a large assortment of Hollywood, Brokeback will probably win for cinematography and best adapted story, and stuff of that nature.
Truman Capote made no effort, at least as an adult, to hide his homosexuality. In fact, even by todays standard, he would be considered a unrepentant flaming queer ... Barny Frank would look straight by comparison.