Basically, spoilers have gone one of two ways recently. Either the entire set is spoiled early, the surprise is ruined and people get banned (or maybe that was just New Phyrexia), or Wizards keeps tight control of the spoilers and rolls them out a little at a time.
But we may have a chink in the armor here.
Looks like WOTC gave a Duels of the Planeswalkers preview to IGN, and some stuff was found that wasn’t supposed to be (wink wink). Look, I have no idea if this was an actual “leak” or done on purpose (solid move on Wizards’ part if so), but it’s cool we’ve got some spoilers. Convoke, as seen on stuff like Sprout Swarm is returning, which could also mean a Chord of Calling reprint to help bring down the price.
We’ll see. In the meantime, you can check out the up-to-date spoilers here, including all the new ones that were possibly “leaked.”