Mostly, there will be no more increase in your mana, due to your intellect. Intellect can only grow your spell power and spell damage. Right now, Spirit is the stat which reproduces your mana more quickly. The reproduction cannot be influenced by the intellect any more. It is easier to find out how it is influencing the regeneration.
Moreover, players are still struggling to get a handle in Mists of Pandaria beta. Gamers is probably focusing too heavily on intellect and regeneration problems. While if you know how it works in detail, the fresh system may function better. You have to worry about 2 stats for various reasons rather than intellect being king for bigger damage.
Almost every class gets a number of mana. The change of mana is fascinating and valuable. It is the change that many players are not sure how to deal with entirely. Classes with multiple specs have bonuses to their mana pool through their specializations.
Players should also consider that how it will affect spell cost. For instance, Priests have 100000 base mana for all specs, so many of Priests spells will get costs. While taking a look at Paladin, you will find out that it costs 35% of base mana for diving light. This requires players to make the costs quite close between classes.