Or at least, add new items that DO give mana regen. There are basically no items with mana regen anymore. Manaless champions got buffs they didn't need, while mana users got hit hard. Teemo no longer has ANY viable mana regen items. Anybody else who wants even a little bit of mana regen is pretty much limited to Chalice now.
Why is it so wrong to be able to build just a little mana regen without having to go whole-hog and buy an item dedicated to it? If you're going to keep this up, you need to raise base mana regen on AP mana-users, otherwise you're pretty much screwing them over completely. You used to be able to build a little mana regen here, a little mana regen there, and not have to go too far out of your way to get it. Now you have to go completely out of your way and build a pretty much dedicated mana regen item. And what have mana users gotten to make up for such an obvious nerf/disadvantage?