The site says the kid may have had some heart defects. Not his fault, but not really the rollercoaster's either. I mean, they don't require extensive tests before riding, and you shouldn't need to do any yourself. It's an unfortunate accident, but it happens.
As for rollercoasters in general, I love them. I used to live in Ventura, CA, and my father and I would visit Magic Mountain at least once a year. Last time I went was through my middle school when Riddler's Revenge was brand new. Holy crap was that one fun. Though I really want to try out X.
A year earlier, on a similar trip with the middle school, two friends and I ended up riding Psychlone at least a dozen times because there was no line for it. Colossus was still better in my opinion. More recently, I've been to Six Flags St. Louis. It's a poor park as far as Six Flags parks go, but the coasters are ok. Batman is the same as in Magic Mountain, and Ninja here is similar to Viper, though smaller.
A favorite is Mr. Freeze,
seen here. One of my friends used to work at the park in high school, and he said the most fun days were the ones where the coaster didn't make it back around that top turn. See, what happens is at the end tower there are electromagnets which lift up the train by pulling and pushing on the metal blades on the sides of the cars. The operator of the ride controls the magnets on the tower. Some days, he lets go of the button too early, and the train doesn't go high enough to build up enough momentum to make the turn. They have extract everybody at the bottom, then send a slow-moving electric train to push the riding train back to the station. All in all, about a 3 hour ordeal.
[edit]It should also be mentioned, that when you are 12 or 13 and think it's really funny to mess with the height of the restraints on Riddler's Revenge, and it happens to lock at the point when you're just shy of standing on your tip-toes, it makes for a rather uncomfortable ride.
Sorry, again.