which means negative utilitarianism that nevertheless values existence
So, you get a constant utility minus however much pain you feel?
It's not negative utilitarianism if it has any positive values. It just doesn't have the normal ones.
Apart from things we caring about getting mentioned, do you think this book is actually valuable?
The Battle for Compassion: Ethics in an Apathetic Universe is a new book by first-time author Jonathan Leighton. He argues for 'negative utilitarianism plus', which means negative utilitarianism that nevertheless values existence. Chapter 13, 'Where We're Headed', discusses the Singularity at some length and mentions Yudkowsky several times. (Click 'Look Inside' on Amazon and search for 'Singularity' or 'Yudkowsky'.)
The book is written for a popular audience and does not reflect my views.