Guys...we already don't have any Mana Regen
What is everyone so fearful of? There's really only two Mage items available (besides Doran's) for any Mage to get Mana Regen -

Doran's Ring is staying the same, and these two items' mana regen were already gutted with the percentage changes. 100% base mana regen is abysmal. You can cast one more spell what, every minute? And Unholy grail kicks in when you're already out of mana. We're already mana starved as is on live, and have been for a long time.
Riot's new changes is just the other half of what they've already started. They've finally giving us much needed mana and CDR on way more items. We can actually pick and choose what we want to build and not just be stuck with nomnomnomicon as a required rush for every single Mage. How in the world is this anything but good?
Open your eyes. Mana Regen is already dead. Once you realize that, introducing Mana on items is very much a welcome change.