Won't be Sparks, they're in Europe in July so wouldn't be coming back in August.
But, jasmine.4.t has a song called Guy Fawkes Tesco Dissociation...
(I know she's playing EOTR as well but she's so far down the line-up that she'd be in the bracket of those that could well play both)
Little Bit Closer has really grown on me! Given he released it a day before the album, I think he'd play that live as it also shows off Brooke's vocals.
In January, the 'more coming soon' teaser arrived a day prior to the 'Announcement tomorrow..' post so I'd agree that we are likely to find out some more this week! Sunrise always seems to house the most interesting acts!