I think they should keep them, though perhaps there should be some simplifying of the rules in this respect. In particular, I think there should be some other mechanic to handle close-combat archery and spellcasting, like requiring a Concentration check or lose the attack/spell (like casting defensively, but compulsory). Perhaps an AC penalty until next round can be applied instead of "minor actions" that currently provoke an AoO.
Of course, this echoes into one's feat choices. Combat Reflexes is not considered an attractive option for any player in my game. They don't like having to rely on a foe making a mistake to use their feats as it is, and if AoO's were rarer, that feat might as well not exist.
Readied actions should be clarified to the extent that there should be no question whether someone can move out of range in response to an attack, and if the attacker can alter his action to something else as a result (since the fighter obligingly moved out of my way, can I continue and attack the mage instead of swinging at empty air like some sort of idiot?). This is more confusing than AoO's in my game.