Mike Rowe, the Dirty Jobs guy, addresses the issue of following your passion in a wide-ranging talk. Money quote: "Follow your passion? Worst advice I ever got." (http://www.youtube.com/watch?v=r-udsIV4Hmc )
I'm not sure that Mr. Rowe is making the correct conclusion about success and passion. Sounds like the passion of the pig farmer who lives in Vegas making a great living feeding his pigs the casino food waste is perhaps making a comfortable living, and he found a clever way to do it (perhaps finding the clever way to best the system is his passion.)
I think defining passion is a tricky business. A passion doesn't have to be playing the violin. Some peoples' passion is simply to be useful--and beyond that they may or may not have creative impulses. When we talk about helping our children to follow their passion, we are not suggesting they become marginal to society and seek out the obscure, rather that they grow into their own skin, that they own themselves, that they are able to define with clarity what their place in the world is.
There are leaders and there are followers, there are pacifists and fighters, there are those who make music and those who enjoy others making music. It takes all to make a world, and if we make that world through a higher consciousness the outcome should be not a happy joy fest, but a richer fuller existence for all.
And finally, this is a life long process. Passions are not all formed by birth; as we grow and change, our passions may grow and change. As parents it is our job to keep holding space for our children to explore that with consciousness. As humans it is our responsibility to hold space for ourselves and everyone else in the same way, suspending judgment and being fully present now.