Mark Rosewater, head of design for Magic: The Gathering has been tweeting spoilers for the newest MTG set. Here are some choice bits of info.
…We explored many graveyard mechanics (like Delve) but ended up with an oldie: flashback.
How about a new ability word: morbid. Morbid makes the spell better if something has died this turn
We also get to see the “Transform” mechanic, which has a second/power and toughness value for a creature after it transforms.
Other spoilers include a Black/Green land in the same style as Glacial Fortress and a card actually called “Wooden Stake”
This set might just be as awesome as we suspect.