There is no 'counter' to aggro shaman but tempo mage, control warrior, zoo, freeze mage, and renolock all have favorable matchups against it.What is the counter to shaman? That is the question...If there is no reasonable counter to it...We should all be playing it. It looks so solid.
I'm talking about tomorrow...Do you really think that tempo mage is viable after tomorrow? We shall see, but I think many of those 'favorable' matchups you mentioned are not as favorable come the new format (I don't give a crap about Wild atm...Just standard.)There is no 'counter' to aggro shaman but tempo mage, control warrior, zoo, freeze mage, and renolock all have favorable matchups against it.
Tempo also loses Unstable Portal...That, with Mad Scientist, sticks a fork in it. Zoo is taking a lot of hits and I find it strange you reference BGH in a deck that would only have 1 BGH...I think RenoLock is already a bad matchup to any focused aggro deck. You need to mulligan and draw well to counter aggro...Having lots of 1 off creatures and a single Reno is not a plan...It is just hoping for a bad player and a good draw.Tempo mage will still be viable but it's gonna be slowing way the hell down without flamecannon and mad scientist and almost certainly won't be favorable against aggro shaman anymore. Hell, even freeze might not be favorable against aggro shaman anymore, with the loss of mad scientist and the addition of flamewreathed. Aggro druid could give freeze mage fits with an early fel reaver, but at least with reaver you still had the option of just keeping it frozen and milling them. The only answer freeze mage has for flamewreath is nova/doomsayer and hoping they don't have an earthshock.
Zoo is gonna have a rougher time without having disposable minions like egg/creeper, but they still might be able to out muscle aggro shaman. Reno lock will be pretty screwed by the BGH nerf though.