I disagree.. while there a certain similarities, especially when it comes to "becoming better" at both playing chess and programming ( it comes harder to improve at a certain level), the whole concept, motivation and purpose is different. Chess is about winning a defined game, with a defined set of moves. The motivation is, primarily, to win the game. Only very few players are playing chess professionally, but most do it as a hobby.
Programming on the other hand is the contrary: it's not a competition. It's about solving problems, so your opponent is not necessarily another developer, but a problem that's complicated to solve. And the solution depends on the exact definition of the problem. I don't see where an equivalent to the elo-score would fit in here, let alone have any use whatsoever.
