The reasoning behind Muse is that they are doing the festival circuit next summer, they have already announced several dates across Europe. So it stands to reason they will play a UK fest. I can't see them headlining Glasto in their current state and based on the rumoured headliners over there. I think they are probably too big for the other UK festivals. So it leaves only R&L left, a fest apparently in need of a rock headliner and a fest they have history of headlining