Another possible talent would be to give us something that really increases our mana bar, possibly without increasing intel or by doing it not entirely from increasing intelligence, which would imply some crit rating increase as well.
So basically, that talent that increases total intellect by 3% each step - it doesn't translate to a mana pool increase of 3% because not all my mana comes from intellect, a ton of it comes from the base mana and health you get from each level, make it increase mana pool by an additional 3% too. Or throw that talent somewhere else so that we actually have something useful to spend our talent points on early in the arcane tree if a 15% mana and 15% intel increase together seem too powerful for 5 talents. Really, I don't think it is, because at most its a slight improvement to crit rating and a 30% or 35% depending on how the math works, increase to total mana. So my mage with 9K mana now has 12K mana. Makes mages more useful at PvE, and not such a big deal at PvP. But warlocks have 13K health and they can simpy life-tap it into mana, allowing them to concentrate on items that stock up on stamina for PvP, so why should mages be able to have awesome mana? I mean mages are by far and away the most deep magic of any class.