I'm sure I'm in the minority, but I was looking forward to improved holy nova more than any other change to priests. The ability to proc instant smites on demand, for free mana, was huge (the 50% crit rate with a group of enemies or friends would virtually guarantee a free smite or second free nova). It really made the PvP smite spec for me.
I hope they bring it back, or make it our basic ability to replace desperate prayer. Otherwise I think the smite spec is dead for me using the holy tree, which is disappointing since there are a few talents aimed at increasing smite damage (chakra for example).
I must admit that I was looking forward to this talent as well, even though less than I was looking forward to Chakra. It would offer Holy Priests their own niche: a quick yet manawasting way to boost the raid's health, which would prove to be useful during critical moments. After proccing Surge of Healing (not sure if it's the correct name) you would even have the choice to either return a part of your mana or go for another Holy Nova to heal a tad more, which fits the flexibility of a Holy Priest.