Well, a major difference here is that 2 months ago this edition was not available. Today it is and people can go online and purchase it and read it (I'm already through chapter 3 of it). Without this post, I, for one, would not have known that I could go online now to read it and would have been waiting for my preorder. And since it's a rainy Sunday this is a great time for me to get some reading in since yard work is out.
a major difference here is that 2 months ago this edition was not available.
That doesn't change the kind of discussion that takes place which is why it's usually the pre-announcements that get downweighted.
Without this post, I, for one, would not have known that I could go online now to read it
Sure but that is at best, a tertiary purpose of HN. Something is always new to someone, relevant to someone, etc. The dupiness or most other on-topic-ness criteria can't really work on that basis.
