People were worried about hitting Emrakul Turn 4 with Aetherworks, now they have to worry about Ulamog. Wait... I know! Let us ban Ulamog! It's too powerful...
Wait... it's supposed to be cast for 10... Not cast for 4!
Emrakul isn't supposed to be hard cast for 13... Maybe 7 but not 4... it's too easy to get Emrakul out, therefore Emrakul is too powerful?
Ultimately
Aetherworks Marvel is a problem and no one cares that a turn 4 play allows you to cast a trigger that is usually restricted to turn 7-10 with energy counters you can't remove. Scandalous!
Mono Black Zombies, like Ladof mentioned, is going to be hit hard post rotation. But that is going into winter, after Hour of
Devastation.
Relentless Dead, Diagraff Colossus,
Liliana, the Last Hope,
Dark Salvation,
Cryptbreaker and
Transgress the Mind. Assuming their loss is not supported by the expansion.
There is diversity, but using energy decks, the focus is still on casting Aetherworks to find a win condition. Mono Black Zombies, Boros Humans are able to deal with it, being
pure aggro, but a turn 4 Ulamog with
exile 2 permanents, stops recursion
dead.
I'd say U/R control -
Torrential Gearhulk.
Mardu Vehicles -
Heart of Kiran/
Gideon Ally of ZendikarTemur energy -
Aetherworks Marvel -
Longtusk CubMono Black Zombies
Orzhov Zombies
Boros Humans -
Always Watching -
Glory-bound InitiateB/G counters -
Walking Ballista -
Verdurous GearhulkThese are all standard GP contenders.