"The Rumor Mill staff has had an anonymous source contact us about the mythic land. We feel it's fairly confirmed, since the source has proven reliable with a separate spoiler. Here's what we know about the other card!
When you have 10 gates, you win the game. It wasn't specified if this was at upkeep or end of turn.
There's less sure things that can be inferred as well. First, the source wasn't sure if it is or isn't a Gate itself. I'm inclined to believe it isn't. Second, it's likely the mythic mentioned in today's Arcana, since it's an alternate win-con. Third, it's probably true, since every pack is going to either have a Gate or a shock, so drafting a deck around it won't be impossible.
So there's the first spoiled DGM card!"
http://forums.mtgsalvation.com/showthread.php?t=483735