Here's my two cents:
Lucinda Williams/Neko Case I could see either playing a mid day headlining set or headlining the Mural Ampitheatre stage, which is typically alt-country type bands.
If Rage is there Anti-Flag will probably open seeing since Anti-Flag announced that they would be on tour this summer with Rage.
I would not be surprised if
shows up as the opener for STP since they are supposedly supporting them on there tour.
Black Keys have opened for Beck before so that is a possibility.
Prince, probably doesn't need an opener, if he is there.
All-American Rejects and Paramore will be headlining I would guess (I don't know how they got so big, but they did.) however, with all the big bands coming to Bumbershoot this year it would have to be during the day.
Having said that last year it was hip hop one night, rock one night and pop one night so I guess we'll see. Beck, STP, Rage, but then where would the Purple One fit in? Which starts to make me think that Rage and Prince might have just been a mistake all along..........July 15th it will all be clear........