The next large set has been announced by Wizards of the Coast, and it goes by Innistrad. The set appears to have a bit of a continuation of the horror theme that we've been seeing as of late with Vampires, giant monsters in the Eldrazi and then the return of Phyrexia.
Right on the front is new art for Liliana, meaning it's quite likely that after the most recent mirrodin block is done we're going to get Liliana 2.0, and possibly the corrupted Garruk that was hinted at in the official webcomic a while back. If the cards are good enough, it looks like black may be the dominating control color in standard after the next rotation. Keep that in mind when making your trades if you already have whatever you need for what you're playing at the moment. It's still half a year away, but there's nothing wrong with being prepared even before the spoilers hit. In short, keep those Swords of Feast and Famine at the ready!