With Mists of Pandaria coming up on the horizon, many holy paladins are looking ahead to the changes that the expansion will bring. Most of the talent and ability info is still very malleable at this point, and as such, I haven't begun to worry or get excited just yet. One thing that we do know is that in Mists, intellect will finish the transformation that it started in Cataclysm. Intellect is going to become a throughput-only stat, as it will stop increasing our maximum mana.
Today, intellect and longevity are nearly synonymous. Replenishment and Divine Plea are two of our largest mana sources, and they both scale off of our intellect. Most paladins are sporting intellect gems and trinkets, and intellect flasks and food fill up our bags. Holy paladins have been leaning on intellect for a long time due to its versatility, and it seemed like the decision to roll spell power into intellect would permanently ensure intellect's role as our best stat. By decoupling intellect and mana, the developers are changing everything we know about gearing a healer.