Everyone in my area is going nuts of shard of the flame and are all main decking it. I understand that 2 is a significant gain in this game but is it really worth main decking? If so how many?

No, it's not really all that good. Against an aggro deck you'd put it face down in your row basically every game.

I've been on both sides of the fence. I started with Dalton (Shard is awful), then moved back (Shard is the bestest thing ever), now I'm kinda in between. The reality is the life gain IS nice, and just what you need to get past those rough early turns vs certain decks. It's bad vs over-sped rush (think Druid or Warrior), but actually quite good vs midrange rush (think Shaman or Hunter, which are the more popular aggros of late). It does almost nothing vs stall; they do little damage early, and tend to kill you in "one fell swoop".

So the real answer to the Shard depends on the meta. Right now (at least in my area), the meta is tending towards Shaman and Ferocity Hunter/Shamans, so it probably deserves its slot in most control decks. Just expect to board it out a fair bit.

Thats pretty much where I am evil dave. I think it could be good in the current meta I just don't see it getting main decked at all. I see more equipment hate being popular from all the gorebelly running around, at least in my meta. Hopefully I won't lose a few matches because of all the health I could have healed. Perhaps I'll sidedeck a few just in case.