To be fair, there are two other things at play here.
* 1. No app had ever displayed books on a bookshelf in this way until Delicious Monster did.
* 2. The designer who designed the bookshelf UI at Delicious Monster was poached by Apple to work on the iPad team.
(And because I'm irritated by comments on Hacker News lately, I just want to point out that sarcasm is the simplest form of humor.)