Even vanilla monsters like Luster Dragon see action from time to time
Counters like Defabricate and Scatter Ray give Blue some good removal options to keep it in the game Blues also got some decent mana sinks in the set with Air Marshal, and Third Path Savant
Although the changes take effect January 6, the information provided by CGC says that those who have entered a submission online prior to that date will still get the lower rate, but they will need to have their cards to CGC by January 20
Pemmin's Aura is exactly that, combining with creatures that generate more than one colored mana to produce infinite resources to cast your spells: You'll see it in Commander decks like Zaxara, the Exemplary, who forms a nice two-card combo with it to help power out various monstrous X spells, and Kinnan, Bonder Prodigy, who helps you go infinite with any old Birds of Paradise
This being able to kill a Planeswalker is pretty good, since otherwise you might need to effectively sacrifice several creatures in combat to swarm the walker down