Conversation so far:
When was their third hiatus?
October 31, 2009, resulting in Slipknot's third hiatus.
Why did they take this hiatus?
several band members focused on respective side projects.
What projects did they work on?
Taylor founded Junk Beer Kidnap Band and returned to Stone Sour with guitarist Root.
What did the other members work on?
Crahan continued working with his band Dirty Little Rabbits.
Were there any other members projects?
Jordison returned with his band Murderdolls and became the new permanent drummer of Rob Zombie.
Was that all of their projects?
Percussionist Fehn is now a full-time bassist with metalcore band Will Haven and Sid Wilson founded the eponymous band Sid.

Question: So the band never got back together?
Self-contained rewrite: Did Slipknot ever get back together?