Oh, I agree.
I didn't say I LIKED that ending - but it was the best ending that Jackson could do, considering the target audience, especially for a first film. I wouldn't be surprised, however, if The Two Towers has the darker ending that finishes that book, since he's got people hooked with the first film. Worked for The Empire Strikes Back, too.
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche