Highly doubt The Decemberists will be there "Colin Meloy has said the group will take a multi-year hiatus once the touring cycle for The King Is Dead ends."
Dunno if what's in quotes is from an agent or anything...but I feel compelled to comment on my favorite band's status.
Their hiatus was in some capacity related to Jenny (their organist/accordionist) having cancer, and to a bunch of the band's members playing in a side project called Black Prairie. Everything I've heard says Jenny has gotten healthy (thankfully), and Black Prairie has dates scheduled through March.
What I really mean to say is that Bonnaroo will be about 20 months (almost "multi-year") since the Decemberists did much. I guess they won't have new material though...so if anybody can give me a reason for optimism...that'd be really welcome.