well as they say, "only the good die young."
it's so sad he died at such a young age, but honestly i think it could have been worse. think about it: he died at the top of his game, he already made his role as the joker legendary before the movie even came out, he didn't have the opportunity to lose his good looks, fizzle out, or make crappy movies as he grew older, they ruled out suicide (so even if he was stressed at least he wasn't so depressed he felt like he should end his life), and people are already comparing him to james dean.
believe me, i'm NOT saying it was a good thing that he died, i'm just saying that if it was his time, it could have been alot worse for him, his fans, and his career.
RIP heath ledger, you will be sorely missed!