The Decemberists have announced a 5/27 Red Rocks show, so they go from likely to definite. Supporting them at Co-headlining that show will be Spoon, who I'm adding to the rumored list now.
Oh hell yeah, really really wanted Spoon. This is good!
Spoon and the Decemberists are actually "co-headlining" that show. I doubt that will affect Sasquatch lineup placement, but who knows. I do think the Decembersists might headline Sasquatch, but Spoon is probably a subheadliner (they were scheduled to subheadline under New Order for Weekend 2 last year).
I didn't know Alice In Chains were active, but they toured last year. Macklemore performs at halftime last year and Alice In Chains this year. A different group of people will go to the bathroom than last year.