The set doesnt go on sale until November 17, 2017, but you can check out the crowd-sourced card image gallery at MythicSpoiler
This was done so the new legendary Spacecrafts can lead decks right out of the box, but the change is permanent and retroactive
Control Control is a defensive, reactive archetype that focuses on disrupting the opponents strategies, employing multitudes of counter-spells, such as Remand, and hand disruption spell,s such as Thoughtseize, in order to survive to the late game and execute their win conditions
Even after just a few attacks, Krenko can out scale plenty of other commanders very quickly
When you ask, the answer is usually the same: Oh this
One other subtle strength here is the degree of control you can have over exactly when cards are milled, and how many (assuming you have painlands or other unrestricted self-damage sources)