The Cure have announced that they will be headlining Bestival on Sept. 10th, 2011. It is being billed as their only European show of 2011 (actually, Robert's quote says "only European festival show"). Tickets are available now. Not a rumor, not a dream, The Cure are playing live again! Thanks for the early Christmas present, RS!
BBC 6 Music has an interview with Rob Da Bank about the show.
Update: About that "only European show in 2011" vs. "only European festival show in 2011" bit - "I’ve asked the promoter to clarify that. RS signed off the press release as it is but he may have overlooked the discrepancy so I’ll let you know once he comes back to me."
And about single day tickets - "There aren’t any plans at the moment to sell day tickets this year but have asked the promoter to confirm that, again once he comes back to me then you’ll be the first to know." (Thanks Aidan)