Preordain's inclusion is due to the loss of Gitaxian Probe. Added to smooth out draws, initial lists tried to not play this card but were found to be slightly inconsistent. Preordain was the perfect remedy for the problem at hand. If you have the option of casting Preordain, Ponder, or Brainstorm on turn one — don't cast Preordain. It's generally better to cast Ponder as it digs deeper. Something to keep in mind is that Preordain fills the "flex spots" in the deck and will likely be one of the first cards sided out in plenty of match-ups.