What you have stated here is the exact reason why Amazon might not carry extra stock (security stock).
1) There is a huge life-span to this product. No need to have it now! Now! Now!
2) They way their model works is by not having huge warehouses filled with stock. They order what they think will sell and since they sold out completely even if they never sell another set it was a complete success. They sold everything they had.
3) They did get confirmation that a second print was being run so they can still fulfill all of the orders taken. There is no need to have stocked up on more because the life-span expectancy is long and it's only going to be a few weeks before they get more. In the long run of the products life that's a very short time.
AND just because some small group of gamers are really excited about this and want it NOW NOW NOW it doesn't mean they should be concerned about that. Obviously those people would have preordered way in advance and their books would be shipping today. If someone didn't preorder soon enough then they must not be that much of a fan compared to all the others who did.
The majority of people are not thinking like the people on this message board, they are waiting but not panicked into thinking that Amazon sucks now and they have no idea what they are doing. There was only so much to go around to begin with and it all sold out. From their point of view they see this as a totally reasonable situation and will sell more books as soon as soon as they get them.
As far as having "extra" stock in their warehouses goes you need to do a little search on the economics of retailers that do business online and how the brick and mortar business model had to change because of the paradigm of doing business on the internet.
