I wonder if people are overvaluing these gtlds. Of the general public, how many people are going to see "great.books" and think "Oh that's a URL I should type."
Exactly. And, more to the point, if they're kept private, they become less novel as people very quickly learn to equate them with Amazon or Google, etc.
The gtld idea only produces significant value when the tld's are used for public registration and diverse use. At least that's my claim/prediction. Otherwise it becomes just a sideshow. Heck, even with open registration it might. Look at .tv or .mobi or .me or any other "valuable" tlds that current exist. They really don't seem to be as disruptive as some may have expected.
This is the best example I've seen. We've spent the last 20+ years training the public that ".com", ".net", etc equals "website". Now that anything could be a URL, it's going to be a lot more confusing for people.
The owners of (books|music|whatever).com are going to be happy because a good number of people are going to see "best.books" and end up thinking that means "best.books.com"
What if some people are already typing this? What if some people have been typing great.books in the Address Bar for years because they just don't how to use a search engine? Is that possible? How much money could you make by capturing all that traffic?