I know that this is an old node, but I just ran into the differences between 1st and 2nd editions. Everyone else is spot on. These are completely different books by different authors. I have no idea why O'Reilly would use the same name and animal for these.

I was so startled, in fact, that this is why I was searching the site for information no these books and ran across this node.

At any rate, the 1st ed book is still available at Amazon and it doesn't say it's out of print, so in answer to your question, you can currently get both editions. This probably just leads to greater confusion, but there it is.