Training grounds: Insane creature.dec would usually run training grounds. For multiplayer, TG seems to run pretty much under the radar until it's too late (when the insane creature hits the board), which means that TG is actually just the premonition. Ironically this is fairly fragile as it only improves efficiency of a repeatable effect (i.e. ones that don't require tapping) but not so much on ones that require tapping and the like. TG combos well with levelers of the same set and also cards like Sliver Queen from older sets.
All is Dust: Minori ranted that AiDs was going to be expensive (and a rare effect in mythic), and lo and behold it is!
Powerful board sweeper and saw constructed play. In multiplayer, this card is EVEN STRONGER due to the fact that it hits nearly everything in plain sight and can be run in any colour to cover up any weakness that colour has (green vs creatures and planeswalkers, black and red vs enchantments, blue vs permanents, white vs planeswalker). Like all board resetters, it is awesome (except this is the most awesome one in multiplayer...). Minori looks forward to hate on this card in the near future (curse those money cards!).
Sneak Attack: 4 mana is usually the major issue with the card. Sneak attack + oversold cemetery + doomed necromancer. You're welcome.
Pestilence: Board sweeper. Pop a pro-black creature to keep this puppy alive forever (until a disenchant shows up). Massive damage to each player also helps too. Minori recommends combo with stuff like sphere of grace (prevents all pestilence damage to you!) as well, because it's that boss. Too bad you can't be in monoblack (which is something easily fixed with urborg).
Slieght of hand: combo looker. Not as good as brainstorm, ponder, etc.
Berserk: Key card in turn 2 wins in 20 life/7 card aggro decks in classic. The ability to double any damage helps a lot and helps power out some insane damage. Terribad in multiplayer though. Oh also affinity wants in.