Junior G-Man: DiCaprio Attached To J Edgar Hoover Biopic

Clint Eastwood and Leonardo DiCaprio are teaming up to take on the complicated life and legacy of J. Edgar Hoover, the founder of the FBI, according to Deadline Hollywood. It should be a juicy story to tell: Hoover, if you're not aware, not only centralized a good amount of federal law enforcement, but also (allegedly) amassed secret files on politicians for the purpose of blackmail, downplayed the existence of the Mafia until it was far too large to bring under control, and started the COINTELPRO program to disrupt the activities of groups like the Communist Party, the Black Panthers, and the Southern Christian Leadership Conference. 
 
A divisive figure, to be sure, and that's not even getting into the rumors of (generally discredited) cross-dressing and (somewhat more accepted) homosexuality. Given that Dustin Lance Black's last screenplay was a biopic of gay icon Harvey Milk, it wouldn't be too surprising to see this film deal with that aspect of Hoover's life in a more forward manner. 
 
It's too bad, though; I thought Billy Crudup did a great Hoover in Public Enemies, and it would've been nice to see him land a big juicy role like this one. But DiCaprio's performance in The Aviator should act as proof that he can slip into biographical roles relatively easily. What do you guys think of this casting?