One of the strongest new interactions from The Boomsday Project in Shaman class is Voltaic Burst plus Flametongue Totem, which gives you two 3/1 minions with Rush. That's a lot of damage taking into account that the entire combo costs only three mana.
However, the main win condition is Bloodlust, which can be supported by cards like Primalfin Totem, Feral Spirit, and Giggling Inventor. If you're still short on damage, then finish off your opponents with two copies of Lava Burst and Lightning Bolt.
The new card, Menacing Nimbus, can give you some powerful unconditional Elementals to play with, and Lightning Storm can clear the board in cases of emergency.