It seems, after the patch, it will be viable to stack INT as a resto shaman.
Before it was better to stack +healing since it was the one stat that helped with mana efficiency and increased the chance you would save someone's life when your heals are bigger.
Now when we can't downrank anymore, there is a big difference in play style. We need to heal less often, but for more. The new HoTs help with that. It also means there is a slight chance you go out of FSR in some situations, and since the last buff to out of-FSR-regen INT also increases that amount.
The change with potions is also a big change in play style, before you could trust your potions to give you mana, now you need the replenishment buff from a fellow gamer, which is based on total mana (0,25% of total mana per second). Mana tide doesn't change, it still benefits from a large mana pool, just as before.
The new talents Improved Water Shield and Ancestral Awakening makes critting alot more attractive. Before the benefits from crit was giving the Ancestral Fortitude buff and increasing the chance of saving someone's life through healing for more (but mostly in pvp situations), it was not dependable. Post-patch the benefits will be much bigger. INT raises your spellcrit chance. The change to the talent Nature's Blessing was favorable, if only by a very small amount (depending on which spell power to +healing conversion factor you use).
Simple math can tell:
11 INT with talent
1.65 spell power
0.125 % crit chance @70
This is calculated 1. for when having the replenishment buff, and 2. with the assumption the fight lasts exactly 5 minutes, any shorter or longer than that and mana tide gives even more mp5, and loads more for each additional resto shaman in the group. It is not calculated for the fact that crit increases your mp5 thanks to the talent Improved Water Shield since it is not easily modeled when using different cast times.
Ember Skyfire Diamond and Improved Blessing of Kings boost these benefits by 2 and 10% respectively.
As always, there is no simple answer regarding healing stats. There is a balance between healing capacity and longevity each player needs to individually adjust to their play style.
How will you decide to enchant and gem with this in regard? Discuss!