There are two big pickups for this deck in the new set: Frontier Siege and Ugin. Frontier Siege is an interesting card in that it is absurdly busted if you can get it into play ahead of schedule. Notice that it says each main phase. That means that Frontier Siege not only helps you cast your big spells ahead of schedule, but also helps you get your remaining mana creatures into play to boost your devotion.
The combination of Ugin, Genesis Hydra, and Polukranos give you all kinds of absurd payoffs for getting your mana engines online, and even give you ways to battle through huge attrition wars with Whip of Erebos decks. As always, this style of deck has some of the most absurd nut draws and powerful end games of any deck in Standard. In this deck, you can lead off with a pair of mana creatures and play Frontier Siege on turn three. Then when you untap you can cast Nissa, Worldwaker, untap your lands, play a Nykthos, and jam Ugin, the Spirit Dragon during your second mainphase. Because Frontier Siege is fair.
There's no doubt that a Green Nykthos deck will be part of the metagame until Nykthos rotates. The question is what the maindeck will look like; what the balance between top end, midrange, and ramp effects has to be. Is Frontier Siege good enough? What about Eidolon of Blossoms? Where does the balance of Hornet Queen, Ugin, and Nissa want to be? There are a lot of interesting questions to ask if this is what you want to be doing in Standard. Personally, I can wait to see people get demolished by turn four Ugin.