As is well known, preview videos and pictures for the Duels of the Planeswalkers video games often have preview cards for the related core set sneakily inserted as well. Since IGN recently released a long Duels of the Planeswalkers 2015 preview, this naturally resulted in a lot of spoilers. More than twenty new spoiled cards were transcribed by MTGSalvation.com user Stapler here.
At 7:31 in the video, there are also two artifacts that appear to be called Hot Soup, costing 1, and Meteorite, costing 5.
Seraph of the Masses 5WW
Creature - Angel (U)
Seraph of the Masses power and toughness are each equal to the number of creatures you control.
Resolute Archangel 5WW
Creature - Angel (R)
When Resolute Archangel enters the battlefield, if your life total is lower than your starting life total, it becomes equal to your starting life total.
Triplicate Spirits 4WW
Put three 1/1 white Spirit creature tokens with flying onto the battlefield.
Paragon of New Dawns 3W
Creature - Human Soldier (U)
Other white creatures you control get +1/+1.
W, T: Another target white creature you control gains vigilance until end of turn.
Marked for Honour 3W
Enchantment - Aura (C)
Enchanted creature gets +2/+2 and has vigilance.
Meditation Puzzle 3WW
You gain 8 life.
Void Snare U
Return target nonland permanent to its owner's hand.
Paragon of Gathering Mists 3U
Creature - Human Wizard (U)
Other blue creatures you control get +1/+1.
U, T: Another target blue creature you control gains flying until end of turn.
Mercurial Pretender 4U
Creature - Shapeshifter (R)
You may have Mercurial Pretender enter the battlefield as a copy of any creature you control except it gains "2UU: Return this creature to its owner's hand."
Chasm Skulker 2U
Creature - Squid Horror (R)
Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, put X 1/1 blue Squid creature tokens with islandwalk onto the battlefield, where X is the number of +1/+1 counters on Chasm Skulker.
Creature - Faerie Rogue (U)
When Quickling enters the battlefield, sacrifice it unless you return another creature you control to its owner's hand.
Coral Barrier 2U
Creature - Wall (C)
When Coral Barrier enters the battlefield, put a 1/1 blue Squid creature token with Islandwalk onto the battlefield.
Jallax, Master Polymorphogist 3U
Legendary Creature - Human Wizard (R)
3U, T, Sacrifice another creature: Reveal cards from the top of your library until you reveal a nonlegendary creature card. Put that card onto the battlefield and the rest on the the bottom of your library in a random order.
Frost Lynx 2U
Creature - Elemental Cat (C)
When Frost Lynx enters the battlefield, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.
Military Intelligence 1U
Whenever you attack with two or more creatures, draw a card.
Soul of Ravnica 4UU
Creature - Avatar (M)
3UU: Draw a card for each colour among permanents you control.
3UU, Exile Soul of Ravnica from your graveyard: Draw a card for each colour among permanents you control.
Cruel Sadist B
Craeture - Human Assassin (R)
B, T, Pay 1 life: Put a +1/+1 counter on Cruel Sadist.
2B, T, Remove X +1/+1 counters from Cruel Sadist: Cruel Sadist deals X damage to target creature.
Flesh to Dust 3BB
Destroy target creature. It can't be regenerated.
Shadowcloak Vampire 4B
Creature - Vampire (C)
Pay 2 life: Shadowcloak Vampire gains flying until end of turn.
Indulgent Tormenter 3BB
Creature - Demon (R)
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature or pays 3 life.
Covenant of Blood 6B
Covenant of Blood deals 4 damage to target creature or player and you gain 4 life.
Target creature gets -3/-3 until end of turn. You lose 3 life.
Rotfeaster Maggot 4B
Creature - Insect (C)
When Rotfeaster Maggot enters the battlefield, exile target creature card from a graveyard. You gain life equal to that card's toughness.
Paragon of Open Graves 3B
Creature - Skeleton Warrior (U)
Other black creatures you control get +1/+1.
2B, T: Another target black creature you control gains deathtouch until end of turn.
Inferno Fist 1R
Enchantment - Aura (C)
Enchant creature you control.
Enchanted creature gets +2/+0.
R, Sacrifice Inferno Fist: Inferno Fist deals 2 damage to target creature or player.
Brood Keeper 3R
Creature - Human Shaman (U)
Whenever an Aura becomes attached to Brood Keeper, put a 2/2 red Dragon creature token with flying onto the battlefield. It has "R: This creature gets +1/+0 until end of turn".
Burning Anger 4R
Enchantment - Aura (R)
Enchant creature has "T: This creature deals damage equal to its power to target creature or player.
Siege Dragon 5RR
Creature - Dragon (R)
When Siege Dragon enters the battlefield, destroy all Walls your opponents control.
Whenever Siege Dragon attacks, if defending player control no Walls, it deals 5 damage to each creature without flying that player controls.
Goblin Rabblemaster 2R
Creature - Goblin Warrior (R)
Other Goblin creatures you control attack each turn if able.
At the beginning of combat on your turn, put a 1/1 red Goblin creature token with haste onto the battlefield.
Whenever Goblin Rabblemaster attacks, it gets +1/+0 until end of turn for each other attacking Goblin.
Paragon of Fierce Defiance 3R
Creature - Human Warrior (U)
Other red creatures you control get +1/+1.
R, T: Another target red creature you control gains haste until end of turn.
Reclamation Sage 2G
Creature - Elf Shaman (U)
When Reclamation Sage enters the battlefield, you may destroy target artifact or enchantment.
Creature - Plant Elemental (R)
When Phytozoan dies, return it to the battlefield tapped under its owner's control at the beginning of his or her next upkeep.
Paragon of Eternal Wilds 3G
Creature - Human Druid (U)
Other green creatures you control get +1/+1.
G, T: Another target green creature you control gains trample until end of turn.
Avarice Amulet 4
Artifact - Equipment (R)
Equipped creature gets +2/+0 and has vigilance and "At the beginning of your upkeep, draw a card."
When equipped creature dies, target opponent gains control of Avarice Amulet.
Obvious highlights: An uncommon cycle of Paragons - 3C 2/2 creatures that pump their on-color friends and tap to grant abilities; a mythic "Soul of [Plane]" Avatar cycle of which the blue one is Ravnica and the green Zendikar, which appear to be a replacement for the Titan cycle as 4CC 6/6s with a keyword and two activated abilities that do the same thing from the battlefield and the graveyard; a Wall theme; Squid tokens; new rare legendary creatures; and... the return of convoke, apparently in at least white and black if not all colors.
All in all, this appears to be a core set chock full of goodies for old as well as new players. Magic 2015 might surprise us!