The Martin Goodman Trail has been around for a long time, and is not quite the same thing as the bike lanes the other commenters are mentioning here.  That poor boy's accident sounds like a freak accident - I know exactly where he was biking, the hill not far from the Boulevard Club down by the lake, and families with children have been riding up and down that hill for decades. 

What happened was very sad, but I'm not sure you can always ensure that every possibility of danger is removed. 

About the only thing I see as a huge change, as someone who's been using cycling as a main form of transportation for a couple of decades,  is the sheer speed at which cyclists are going at these days.  It's a combination of new types of bicycles lending themselves to that speed, and a kind of competitive edge cyclists have today they didn't use to years ago.  I've been knocked down on the street by a bike, and riding the downtown bike lanes sometimes feels almost as risky as the road.