Q: Is your goal to make everything picked the same amount of times? (from j.walsh)
A: I don't think about it that way exactly. Sure it's good if there is a nice distribution and that is something to work towards, but really the goal in DotA's development is, first and foremost, to make the gameplay quality the best it can be. It is the combination of all the heroes, items and mechanics together that makes DotA what it is and not the individual elements alone. Sometimes that means certain things are carefully adjusted to be more frequent than others, sometimes it doesn't, but ultimately the main judge of a game's quality is not in some artificial balance metric, but in the overall gameplay quality and depth that it has.