We have only seen a handful of cards spoiled so far and we can already point out some themes of the set
Iconic Cards Zendikar : The enemy-colored fetch lands (Scalding Tarn, Arid Mesa, etc.) Spell Pierce Valakut, the Molten Pinnacle Goblin Guide Worldwake : Rise of the Eldrazi : Emrakul, the Aeons Torn Kozilek, Butcher of Truth Ulamog, the Infinite Gyre Inquisition of Kozilek Splinter Twin Positives: Lands focus gives Zendikar a unique feel
You have good Learn cards in blue and green, make sure you get some good lessons too
This is why I felt unblockable could be red
Alluring Scent Armed // Dangerous Bloodscent Breaker of Armies Declare Dominance Destined // Lead Elvish Bard Gift of the Deity Golgari Decoy Indrik Umbra Lure Marble Priest Mortipede Nath's Elite Nemesis Mask Nessian Boar Noble Quarry Ochran Assassin Prized Unicorn Revenge of the Hunted Roar of Challenge Seton's Desire Shinen of Life's Roar Stone-Tongue Basilisk Talruum Piper Taunting Arbormage Taunting Challenge Taunting Elf Tempting Licid Treeshaker Chimera You Look Upon the Tarrasque
the company wants to avoid the notion of sending children to fight and die for what I hope are obvious reasons