Just throwing in here to say that I read [i]Bounce[/i] last month, and it was fascinating. The stories of László Polgár (who raised his three girls as a psychological/sociological experiment to be some of the greatest chess grandmasters the world has seen) and Richard Williams (father of Venus and Serena Williams, who decided to raise tennis champions -- and he had no real idea about tennis -- after seeing a tennis player receiving a hefty winnings cheque on TV) were at that crossroads between amazing and terrifying.
A really recommended read.
While reading it, I realised that my 10,000 hours have probably been spent playing, listening to and mentally analysing music, rather than physically practising any one particular instrument. That's why, as a general rule, if I've heard a pop/rock song a couple of times, I can generally sit down at any one of three or four instruments and play it for you. I'm not that great (by any stretch of the imagination) on any instrument, but I've got music [b]in[/b] me.