Why retire her?

[justindew]

Zenyatta seems to be at the top of her game, or at least still capable of beating the best (and by "best" I mean all that we have in America). I think if you re-run the Classic 10 times, she wins it just as many times as Blame, if not more. So why not keep her in training and point for the Dubai World Cup and then the 2011 Classic? Retiring her makes little sense to me.