Too many posts to read over. I'm sure forked lightning was discussed, but does this up the value of frost shock? Decent chance of getting spell power, but also you can get a tiny heal on t6 with the 2 cards and stop their biggest creature for a turn. Probably isn't enough value to consider playing, but maybe with yogg saron in mind.
Should I get this or Fandral Staghelm? (Assuming that I have most stuff for both classes and want to use both - which is more essential to a top tier deck in its class?)
It seems like control shaman is still not a thing. Hallazeal the Ascended is a good card but didn't find its place in any existing decks imo. After the meta settles if shamans need healing, the card will definitely see play. Fandral Staghelm is also being experimented in midrange-beast druids. It seems good for now but we don't know if the deck will be solid enough in the new meta. You should wait for a while.