These are my guesses based on some facts, some probability, and a lot of hunch/wishlist. It is not the actual lineup! For those who know how to count, you are correct, this isn't 50 acts. I'll add more in the next couple days. It's a rough draft, so changes will be made. Typically I avoid predicting comedians, so I'm not going to use Nick Offerman to pad my stats.
NOTE: Regarding Primavera, the festivals share acts every year. Yes, Primavera was a different weekend than Sasquatch last year, but it was the same weekend the previous years, and they still shared a handful of bands. If you've ever flown from the east coast to the west coast, you know with the time change, you land only a couple hours later. It's similar flying from Europe. Primavera also is a Thursday-Saturday festival, while Sasquatch is Friday-Monday. A band playing Thursday at Primavera could fly from Europe to Seattle, continue flying west, fly around the world back to Europe, then on to Seattle for a second time, and still make it in time for a Monday Sasquatch set.
Mumford & Sons / Deadmau5 / Sigur Ros / The Knife / Knife Party / Every Other Band Containing the Word Knife / The xx / Vampire Weekend / Postal Service / Bassnectar / Kendrick Lamar / Hot Chip / Yo La Tengo / Macklemore & Ryan Lewis / Arctic Monkeys / Built to Spill / Foals / Empire of the Sun / Beach House / Tame Impala / Tegan & Sara / Flying Lotus / Japandroids / Dinosaur Jr. / The Lumineers / Franz Ferdinand / Infected Mushroom / Amon Tobin / Father John Misty / Black Rebel Motorcycle Club / Portugal. The Man / Akron/Family / A DJ With a Neat Light Show / Solange / Surfer Blood / The Cults / Grimes / Menomena / Atlas Genius / Deerhoof / Disclosure / Dillon Francis / Imagine Dragons / Wild Nothing / Gold Panda / Theophilus London / DIIV / A Guy With A Mustache / Cody ChesnuTT / Blondfire / Seattle Rock Orchestra performing the songs of Mother Mother / Suuns / Mother Mother
Post your top 50 guesses in the comments, if you dare...