Available now from all good bookshops (including Waterstones) and Amazon UK. There is some issue with Amazon US, it seems: you can buy the audiobook for dollars [update: as per the comment below, it seems you can't, actually] but not the actual book. I'm not sure why, and will look into it. 
Is it any good? I'm hardly the person to say yes, or no, and you doubtless have better things on which to spend your money. Brian Clegg describes it as ‘wow’ and says: ‘the mix of a snowflake utopian future, ...