Try and know your match-up: if it's mirror, try and get at much tempo and value as possible. Against the new tempo warrior, your 2-drops might be useless, and so you might want to focus more on turns 3-5.
This Shaman deck got me from rank 9 to 5 on the first day of the August nerfs! I had an 80% winrate, only losing to Highlander Mage, Tempo Warrior, and a mirror.
A lot of people have also removed Mutate, which I think is a mistake. For one, it works perfectly with Former Champ and Mogu Fleshshaper. But more importantly, it can give you early tempo against Rouges and Tempo Warriors (which seem really popular) by playing it on sub-par minions like Novice Engineer and EVIL Cable Rat.
Let me know what you think!