Hearthpwn

You all seem to be severely underestimating that stealth. It practically guarantees that you'll be able to run a huge combo off it the next turn, whereas Brann was so likely to die the same turn you played it that you could only reliably play it late game with smaller cards on the same turn. And you can have two of them.

It also applies to Combo cards. Some of which are incredibly strong, like Vancleef.

you are not really guaranteed that this will survive.

Mossy Horror

Void Ripper

Stampeding Kodo

hope I get a gold drop.

Its just very good. In some way its better then Brann. I guess it may become autoincluded in every rogue deck except aggro (coz its highly depends on drawing Fungalmancer) and I guess quest (its too demanding to have only perfectly fit cards). Double tess, double spooders, double minstrel, double any card you stole. Even just double SI7.

However, on its own it doen't do anything at all. And You will need to git ride of something to include it. So I may be wrong. New meta may become too aggressive to allow you pay 4 mana and do nothing

I don't know, with the actual cards we have I don't really see what I could possibly want to double up by paying 4 mana for a 0/3. I mean ok, in theory it's nice to double up the spiders. But it's a lost worst than actually just playing two 4/4s on the board, or even one 4/4 and the 3/4 elephant, and both have the same effect in the end.

I think it's too expensive for the ridiculously bad stats it has. You're also talking about SI:7, but man turn 7 this + SI:7 is a very bad turn xD. And if you play this on 4 to hope to get one or 2 double combos/battlecries on turn 5, yeah you better get good ones, because you basically passed your turn 4 doing nothing to try to catch up the next turn.

But as always with effects like these, we'll need to see the rest of the set to really judge the card, but we'd need a crazy broken combo/battlecry card to make this card close to good imo. And with the current cards we have it's trash.

*Jaws theme playing*

38 damage combo over 2 turns is possible:

Spirit of the Shark (4 mana)

Worgen Infiltrator (total 2 damage 5 mana)

Fungalmancer (total 10 damage 10 mana, make board resistant to board clears)

Shadowstep Fungalmancer 

End Turn

discounted Fungalmancer (total 18 damage 3 mana)

Crazed Chemist (total 26 damage 8 mana)

Abusive Sergeant (total 30 damage 9 mana)

Abusive Sergeant (total 34 damage 10 mana)

Shadowstep and replay Abusive Sergeant (total 38 damage 10 mana)

instead of doing that if you expect taunts you can Shadowstep the Crazed Chemist earlier in the game so that you can Sap as well on turn 2.

That 1 turn Stealth is pretty big. You can set this and can easily play 10 mana worth of battlecry minions next turn, like C'Thun.