Bow and arrow against plated or heavy armor is pretty much a rotten deal. Great skill should be required to find a weak spot, depending on armor material and armor type (chain, plated etc). An archer is a defender or a hunter, not an attacker. Ideally you should couple it with poison use (so that one arrow that does penetrate, does so greatly), combined with Dagger or Short Blade skills (if we had them), and/or some magic use.
We should also have short bows, long bows, and crossbows, with different effects on fatigue, aiming accuracy (skill vs weak spots), reload time, and arrow speeds (translates to concussion effects for heavy arrows). Arrows should also have balance between penetrating damage and concussion damage against heavy armor. Against some foes penetration is desired, whereas against others concussion is desired. Steel would be light arrows, daedric would be heavy. Daedric arrows against a thick skinned beast like a bear would not be the best choice. I would also like to have backtracking speeds associated with the archery skill, as at least currently it is way too easy to keep dodging incoming arrows.