taken from Wikipedia:

"Possible Future Break-Up
On May 4, 2007, MTV.com released a statement by Corey Taylor in response to rumors that the band would break up after their next album. Taylor responded by saying that "[Slipknot fans] are very pessimistic, and instead of looking at things in a pragmatic mindset, they go, 'Oh, I can't live.' Please." Taylor also said that the band was unsure what will happen after SlipKnoT's release of their next album, for which recording will begin in January 2008. "Nothing's really been written yet, and it's just kind of up in the air right now," Taylor said. "We're definitely going to do at least one more Slipknot album, let's put it that way. But after that, who knows? You get to a point in life where you've said all you can really say with one thing, and I've still got some stuff I want to say with Slipknot. But who knows where I'll be after that. So I want to at least make one more, and then I don't know what's going to happen."