Remove "click-to-move". That's all it would take to kill 90% of the botting population.
Most mainstream (ie. readily available for download for around 10 dollars) bots and gliders for WoW use click-to-move to navigate the game world, in addition to heavily scripted macros. Without this function, it would be nigh-impossible to create any efficient botting programs, and thus less people would be exploiting the game. This is due to the fact that bots which try and navigate using keystrokes often / nearly always get stuck / lost / killed.
Furthermore, I've NEVER seen or met a player who actually uses this functionality (I've been playing since early 2007), so I don't think it would be that big of a deal for the players themselves.
Thoughts? Why hasn't Blizzard realized this? Surely it's easier than plowing through reports and tickets and individually banning people...