White's creatures get shifted around to make room for new Tarkir Dragonstorm cards. I'm most interested in Voice of Victory as a Lurrus-able Hero of Bladehold. Tokens seem to be getting stronger. Thalia's Lieutenant replaces Winota because humans have more low mana value creature than high, so buffing them is better than cheating them in.
Black gets some new tools in place of the more underwhelming reanimation cards.
Forked Bolt was never good, so it gets a similar, but better replacement. Cori-Steel Cutter is an interesting new card from Dragonstorm that Jo will probably be interested in. It's likely more of an Izzet card.
And some other experimental additions.
Additions CutsWhite now has access to more cards that synergize with the other main archetypes in the cube. The goal is to pull drafters into white for reasons other than just aggressive creatures and removal.
Green's 1-mana ramp options have been reduced and replaced with 2-mana variants. The goal is increase the difficulty of ramping out a 3-drop on turn 2 and also to add more synergistic variety to the ramp cards. To accommodate this change, green's creature suite has been re-tooled to reduce the number of 3-drops.
Black has received a power boost and support for a reanimator archetype. The reanimation has been limited to turn 3 in order to minimize non-games.
Changing the ramp package to reduce the number of 1-mana elves and boosting delirium.
Bringing white into the lands archetype.
The Aetherspark just looks cool.