I think one of their greatest weaknesses will be what our children face, as a generation. We live in wild times. Booming global population, increased globalization (globalization has many benefits, but is also comes with many a dysfunction, challenge and risk), environmental devastation, political unrest (always has been present, but due to a globalized economy , has more of a global impact), chemical/biological/military warfare, and technology that surpasses the imagination. Add to that health issues (obesity, diabetes, heart disease, cancer, etc.) and a disappearing middle class.
I'm not sure that they'll have the tools to deal with the world that we have created.
On a less dramatic note, I feel one of the saddest changes, even since my childhood, is the loss of freedom that children have. When I was a child in the 80's and 90's I spent MOST of my day chasing dreams and climbing trees. I knew to avoid rattle snakes, poison oak and cars. For the short time that we lived in town, all of us neighborhood kids would congregate and play in the street. Doesn't seem like that is the norm any more.
Playing outdoors, I learned many a valued lesson: When you fall down, brush yourself off and get back up, teamwork, the value of one good friend, common sense, independence, how to never be bored, how to trust myself (and when to not trust), etc. Fresh air is good for the body.
I think their strengths *might* include tolerance, a fight towards equality, adaptability, resilience and innovation (although it may come out of necessity, later in time). I hope so, at least.