I think you are missing part of the results of Ericsson's research. He makes a very specific point to distinguish practice from deliberate practice. 10000 hours of practice is very different from 10000 hours of deliberate practice.

My interpretation of Ericsson's work is that natural talent can give certain individuals a head start in the beginning, but once you get into the domain of expertise, this head start at the beginning is very tiny and the effects of practice completely overpower it in comparison. However, I think in areas like sports - genetics do play more of a role. If you are less than 5 feet tall, you probably will not be an NBA point guard, even after 10000 hours of deliberate practice.

One of his papers for further reading:

From The Role of Deliberate Practice in the Acquisition of Expert Performance

"Consider three general types of activities, namely, work, play,and deliberate practice. Work includes public performance, competitions, services rendered for pay, and other activities directly motivated by external rewards. Play includes activities that have no explicit goal and that are inherently enjoyable. Deliberate practice includes activities that have been specially designed to improve the current level of performance."

http://graphics8.nytimes.com/images/blogs/freakonomics/pdf/D...