Thanks for your input. Rotated bitboards were invented by Robert Hyatt, who no longer does chess research but still maintains crafty. He is here: http://www.cis.uab.edu/info/faculty/hyatt/hyatt.html
I didn't cover rotated bitboards for a few reasons. However, I made a mistake in not even mentioning them.
One reason was just space. This isn't a site about chess or AI and we just wanted to introduce Java programmers to these methods and show a real world example. To cover the rotated bitboards in detail would have exploded the size of the article.
Another reason was the audience the article is intended for. The OnJava readers are mostly corporate programmers, probably only a few write AI and very few are writing chess software. So the article is not meant to be a how-to on writing a chess engine. Care was taken to make sure that it was correct in regards to chess, but it is not complete. In other words, if your writing chess software this could be a good introduction but you want to keep reading.
While I didn't cover the rotated boards or other chess programming issues they are interesting topics so anyone who like this article might want to check them out.