There will be two competitive Constructed formats: Core Constructed is the main rotating format (like Standard in Magic: The Gathering), where the sets will rotate in every year in four-set blocks, and a new non-rotating format called Infinity Constructed where all sets will be legal
Abzan Charm, for example, is a premium card that any player in the Abzan colors would love to add to his or her deck
Createrhoof gives all your creatures trample when it comes into play, which is pretty good on its own, but also gives them all +X/+X, where X is the number of creatures you control
Sleeves also help with organization
Katakuri has been outpaced by newer Yellow leaders
It works just like Infinite Impermanence except instead of needing an empty field, it requires an empty graveyard