Interestingly enough, 1 AP = 0.50% Crit = 0.25% Haste. This depends on how much AP you have though, as you get more AP it takes less crit and less haste to match the damage.
4 AP : 2% Crit : 1% Haste is a pretty close, general ratio.
Someone just needs to tell me how much Crit / Haste rating =...