Important: Higher Chance of Opening Faction Cards Bug
Blizzard just confirmed that there is currently a higher chance of opening faction cards in Mean Streets of Gadgetzan packs. We suggest not opening your packs until this is resolved.
We will update this post when we have more info.
Quote from PlayHearthstoneWe are currently aware of reports of players having a higher chance of opening tri-class cards in MSOG packs and are looking into it.
Mean Streets of Gadgetzan Pack Simulator
We've updated the Gadgetzan pack simulator to be more true to the real thing. I wonder what you'll get!