Being a resto healer through all of BC and half of wrath, I had always wondered if shamans were going to get something to reduce/gain back our mana comsumption. Well, in Blizzard fashion they decided to give us 2..Focused insight and Telluric Currents. The question now becomes.. which to take?
It is my feeling that it is really up to each individual shamans play style and what raid is occuring. For example- During Firelands raids when there was little time for a healer to cast anything but a heal (save Alysrazor’s burn phase), I was my personal opinion that Focused Insight ( 75% mana reduction of next heal and 30% increased effectiveness of heal) was a better option for shamans to take. (only because in the time it takes to cast a lightining bolt to gain mana and then cast a heal spell, someone could die)
But now with Dragon Soul out and looking beyond into MoP (which i am on Beta when its released so blogs about shamans will be coming) There are more fights where Resto can attack more during boss fights, so it seems like Telluric Currents (restores 40% of lightining bolt damage to target back as mana) is the better way to go.
So my opinion is this… try them both out and see which one you feel is better suited for your play style.