Well, from the little I've read about it so far, Max Payne 2: The fall of Max Payne, is well deserving of its M rating. Apparently they drop the F bomb on more than occasion, the violence is very graphic (I would guess this is because of the slow-mo effect), there's a lot of Obsession and some making out (leading to the Sexual Themes thing) etc etc.
But, it doesn't appear to have just been put in the game for the heck of it. The guy who played it said everything was natural, it wasn't forced, it's the maturity level of the modern world. Beat cops talk like beat cops...
Unfortunately I won't be getting the game anytime soon, the money I had set aside for a new graphics card has been used purchasing a copy of Windows XP -- Macromedia Studio 2004 doesn't support vanilla 98.
Hmm, maybe PC Gamer will have a demo...
*plays theme music again*